feat: implement profile activation and runtime identity clarity (#131)

Add three read-only capability-discovery tools so new LLM sessions can
learn the workflow rules and available project skills from the MCP
server instead of long pasted operator prompts:

- mcp_get_control_plane_guide: active profile, authenticated identity
  (fail-soft; unresolved identity returns STOP instructions),
  allowed/forbidden operations, profile-aware guidance (author profiles
  are told review/approve/merge is forbidden; reviewer profiles are told
  review/merge requires eligibility checks and a pinned head SHA; mixed
  profiles get a misconfiguration warning), and the standing rules: hard
  stops, fail-closed behavior, head-SHA pinning, merge confirmation,
  redaction, author/reviewer/merger separation, profile switching, and
  identity verification.
- mcp_list_project_skills: registry of ten project workflows (issue
  authoring, PR creation, PR review, PR merge, issue comments, profile
  switching, redaction/security review, Jenkins read-only, GlitchTip
  read-only, release/operator) with description, when-to-use, required
  operations, status, and per-profile availability. Unimplemented
  services are listed as designed-not-implemented rather than omitted.
- mcp_get_skill_guide: step-by-step guide per skill; unknown names fail
  closed with the list of valid names.

All three are read-only and change no existing gate or permission.
Normal output contains no endpoint URLs or keychain IDs; the guide
includes the server host only under GITEA_MCP_REVEAL_ENDPOINTS=1.

Tests (tests/test_operator_guide.py, 17 new): profile-aware guidance
for author/reviewer, unresolved-identity STOP, read-only behavior,
redaction defaults and reveal opt-in, rules coverage, registry
completeness and profile awareness, unimplemented-service marking,
fail-closed unknown skill names.

Docs: llm-workflow-runbooks.md now tells new sessions to call the guide
tools first.

Closes #128

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/gitea-execution-profiles.md

@@ -179,6 +179,30 @@ allowed/forbidden membership check):
   therefore never silently widen permissions.
 - An empty or missing `allowed_operations` list denies everything.
 
+## Issue comments versus PR reviews (#126)
+
+Issue discussion comments and PR reviews are different capabilities and are
+gated by different operations:
+
+- **Issue comments** (`gitea_list_issue_comments`, `gitea_create_issue_comment`)
+  post to and read from an issue's discussion thread
+  (`/issues/{n}/comments`). Listing requires `gitea.read`; creating requires
+  `gitea.issue.comment`. They never submit review verdicts.
+- **PR reviews** (`gitea_review_pr`, `gitea_submit_pr_review`) submit
+  approve/request-changes/comment verdicts on pull requests
+  (`/pulls/{n}/reviews`) and are gated by the `gitea.pr.*` family
+  (`gitea.pr.review`, `gitea.pr.approve`, `gitea.pr.request_changes`,
+  `gitea.pr.comment`).
+
+A profile holding the full PR review/merge set still cannot post issue
+discussion comments unless it also allows `gitea.issue.comment`, and vice
+versa — neither family implies the other. Both comment tools require an
+explicit issue number; the target repo comes only from the standard
+remote/org/repo arguments. Create operations are audit-logged
+(`create_issue_comment`) when `GITEA_AUDIT_LOG` is configured, errors are
+redacted, and normal output contains no endpoint URLs
+(`GITEA_MCP_REVEAL_ENDPOINTS=1` is the local admin opt-in for web links).
+
 ## Identity and fail-closed rules
 
 Before **any** mutating action, a workflow must know both:
@@ -228,6 +252,26 @@ the "one server per trust boundary" model described in
 [`tool-boundaries.md`](tool-boundaries.md) and
 [`credential-isolation.md`](credential-isolation.md).
 
+## Profile Activation and Runtime Identity Clarity (#131)
+
+To make Gitea MCP profile activation and runtime identity state explicit, the following mechanisms are supported:
+
+### 1. Static-Profile vs. Dynamic-Profile Mode
+- **Static-Profile Mode (Default):** The active profile is fixed at server launch based on the `GITEA_MCP_PROFILE` environment variable (with `GITEA_MCP_CONFIG` pointing to the config path). Local environment variables are static once a subprocess is spawned by the host. Modifying the environment variables on the host does not dynamically update an already-connected MCP server process.
+- **Dynamic-Profile Mode:** Profile switching via the `gitea_activate_profile` tool is supported **only** if the configuration JSON explicitly opts in by setting `"allow_runtime_switching": true` under rules or top-level keys. Otherwise, attempting to switch profiles dynamically will fail closed.
+
+### 2. Dual MCP Namespaces Recommendation
+For security-sensitive or high-risk tasks, the preferred safety model uses separate, isolated MCP server instances (namespaces/sessions) launched with static profiles:
+- `gitea-author`: Exposes tools configured with author permissions; cannot perform approvals or merges.
+- `gitea-reviewer`: Exposes tools configured with reviewer permissions; used for PR reviews and merges.
+This layout maintains physical separation of credentials and prevents privilege escalation within a single session.
+
+### 3. Verification Post-Switching
+When dynamic profile switching is enabled and a profile is activated via `gitea_activate_profile`, the session MUST immediately:
+1. Clear the cached identity.
+2. Call `gitea_whoami` with the target remote to prove and verify the fresh Gitea authenticated identity.
+This guarantees the active profile operations align with the actual Gitea authenticated user credential.
+
 ## Relationship to roadmap issues
 
 This document defines the **model only**. Related work is tracked separately

docs/llm-workflow-runbooks.md

@@ -18,6 +18,17 @@ behavior they rely on already exists (canonical runtime profiles, the
 interactive setup menu, identity/eligibility checks, gated review/merge, and
 audit logging). See [Related documents](#related-documents).
 
+> **New session? Call the guide tools first (#128).** Before using any other
+> Gitea MCP tool in a fresh session, call `mcp_get_control_plane_guide`
+> (read-only): it reports the active profile, authenticated identity,
+> allowed/forbidden operations, profile-aware do/don't guidance, and the
+> non-negotiable rules (hard stops, fail-closed behavior, head-SHA pinning,
+> merge confirmation, redaction, author/reviewer separation, profile
+> switching). Then call `mcp_list_project_skills` to discover the available
+> project workflows and `mcp_get_skill_guide(<name>)` for step-by-step
+> instructions. This replaces long pasted operator prompts for the standard
+> rules; operator prompts still control task-specific scope.
+
 For cross-project use, copy the portable workflow skill at
 [`../skills/llm-project-workflow/SKILL.md`](../skills/llm-project-workflow/SKILL.md).
 It extracts the issue-first, isolated-worktree, no-self-review, profile-safety,

gitea_config.py

@@ -192,11 +192,32 @@ def config_path():
     return (os.environ.get(ENV_CONFIG_PATH) or "").strip() or None
 
 
+_active_profile_override = None
+
+
 def selected_profile_name():
     """Return the selected profile name from the environment, or None."""
+    if _active_profile_override is not None:
+        return _active_profile_override
     return (os.environ.get(ENV_PROFILE) or "").strip() or None
 
 
+def is_runtime_switching_enabled(path=None):
+    """Check if runtime profile switching is explicitly enabled in config."""
+    try:
+        config = load_config(path)
+    except Exception:
+        return False
+    if not config:
+        return False
+    rules = config.get("rules") or {}
+    if rules.get("allow_runtime_switching") is True:
+        return True
+    if config.get("allow_runtime_switching") is True:
+        return True
+    return False
+
+
 def load_config(path=None):
     """Load and minimally validate the canonical JSON config.
 

mcp_server.py

@@ -597,6 +597,83 @@ def gitea_check_pr_eligibility(
     result["eligible"] = len(reasons) == 0
     if result["eligible"]:
         reasons.append("all eligibility checks passed")
+
+    # Add enhanced error clarity details (#131)
+    auth_user = result["authenticated_user"]
+    pr_author = result["pr_author"]
+    profile_name = result["profile_name"]
+    is_self = bool(auth_user and pr_author and auth_user == pr_author)
+
+    result["active_identity"] = auth_user
+    result["active_profile"] = profile_name
+    result["self_author"] = is_self
+
+    # Determine missing permission
+    missing_perm = None
+    if not op_ok:
+        missing_perm = f"gitea.pr.{action}" if action in ("approve", "request_changes", "merge") else f"gitea.{action}"
+
+    result["missing_permission"] = missing_perm
+
+    # Determine required profile
+    req_profile = None
+    if action in ("approve", "request_changes", "review"):
+        req_profile = "A profile with reviewer role permissions (allowing approve/merge/review, and forbidding author operations)"
+    elif action == "merge":
+        req_profile = "A profile with reviewer role permissions and explicit merge permission"
+    result["required_profile"] = req_profile
+
+    # Determine required identity
+    req_identity = None
+    if is_self:
+        req_identity = f"Any Gitea user other than PR author '{pr_author}'"
+    result["required_identity"] = req_identity
+
+    # Determine if fixable by profile switch vs requires different namespace
+    switching_supported = gitea_config.is_runtime_switching_enabled()
+    fixable_by_switch = False
+    req_different_ns = False
+
+    if not op_ok:
+        config = gitea_config.load_config()
+        has_capable_profile = False
+        if config:
+            for name, p in (config.get("profiles") or {}).items():
+                p_allowed = p.get("allowed_operations", [])
+                p_forbidden = p.get("forbidden_operations", [])
+                ok, _ = gitea_config.check_operation(action, p_allowed, p_forbidden)
+                if ok:
+                    has_capable_profile = True
+                    break
+        if switching_supported and has_capable_profile:
+            fixable_by_switch = True
+        else:
+            req_different_ns = True
+
+    result["fixable_by_profile_switch"] = fixable_by_switch
+    result["requires_different_namespace"] = req_different_ns
+
+    # Determine safe next step
+    safe_step = "Ready."
+    if not result["eligible"]:
+        if is_self:
+            safe_step = "Self-review/self-merge is forbidden. Ask a different operator/reviewer to review and merge this PR."
+        elif not auth_user:
+            safe_step = f"Ask the operator to configure valid credentials/token for profile '{profile_name}'."
+        elif not op_ok:
+            if fixable_by_switch:
+                safe_step = f"Switch to a reviewer profile by calling gitea_activate_profile with a profile that allows {action}."
+            else:
+                safe_step = "Switch to the reviewer MCP session (e.g. gitea-reviewer) which has reviewer permissions configured, or ask the operator to update GITEA_MCP_PROFILE to a reviewer profile."
+        elif result["pr_state"] != "open":
+            safe_step = "No action can be taken on a closed/merged PR."
+        elif action == "merge":
+            if result["mergeable"] is False:
+                safe_step = "Address conflicts in the PR branches first, or wait for CI checks to pass before merging."
+            elif result["mergeable"] is None:
+                safe_step = "Wait for Gitea to finish calculating mergeability or trigger a re-check."
+
+    result["safe_next_step"] = safe_step
     return result
 
 
@@ -1364,6 +1441,583 @@ def gitea_view_issue(
     }
 
 
+def _issue_comment_gate(op: str) -> list[str]:
+    """Profile permission check for issue-comment tools (#126).
+
+    Issue discussion comments are gated separately from the gitea.pr.*
+    review/merge family: listing requires ``gitea.read``, creating requires
+    ``gitea.issue.comment``. Returns a list of block reasons (empty = allowed);
+    an unreadable profile fails closed.
+    """
+    try:
+        profile = get_profile()
+    except Exception as exc:
+        return [f"profile could not be resolved (fail closed): {_redact(str(exc))}"]
+    op_ok, op_reason = gitea_config.check_operation(
+        op, profile["allowed_operations"], profile["forbidden_operations"])
+    if op_ok:
+        return []
+    if op_reason == "no-allowed-operations":
+        return ["profile has no configured allowed operations (fail closed)"]
+    if op_reason == "forbidden":
+        return [f"profile forbids '{op}'"]
+    if op_reason == "invalid-forbidden-entry":
+        return ["profile has an unrecognized forbidden operation entry (fail closed)"]
+    return [f"profile is not allowed to {op}"]
+
+
+@mcp.tool()
+def gitea_list_issue_comments(
+    issue_number: int,
+    limit: int = 50,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict:
+    """List discussion comments on a Gitea issue.
+
+    Read-only. Issue discussion comments are distinct from PR reviews: this
+    reads the issue comment thread and never touches review endpoints. The
+    profile must allow ``gitea.read`` (fail closed otherwise).
+
+    Normal output is LLM-safe: no endpoint URLs. Set
+    GITEA_MCP_REVEAL_ENDPOINTS=1 (admin/debug opt-in) to include each
+    comment's web link.
+
+    Args:
+        issue_number: The issue number whose comments to list (required).
+        limit: Max number of comments to return (default: 50).
+        remote: Known instance — 'dadeschools' or 'prgs'.
+        host: Override the Gitea host.
+        org: Override the owner/organization.
+        repo: Override the repository name.
+
+    Returns:
+        dict with 'success', 'issue_number', and 'comments' (each with 'id',
+        'author', 'created_at', 'updated_at', 'body'); on a permission block,
+        'success' False and 'reasons' with no API call made.
+    """
+    reasons = _issue_comment_gate("gitea.read")
+    if reasons:
+        return {"success": False, "issue_number": issue_number,
+                "reasons": reasons}
+    h, o, r = _resolve(remote, host, org, repo)
+    auth = _auth(h)
+    api = f"{repo_api_url(h, o, r)}/issues/{issue_number}/comments"
+    comments = api_request("GET", api, auth) or []
+    reveal = _reveal_endpoints()
+    out = []
+    for c in comments[:limit]:
+        entry = {
+            "id": c["id"],
+            "author": (c.get("user") or {}).get("login", ""),
+            "created_at": c.get("created_at"),
+            "updated_at": c.get("updated_at"),
+            "body": c.get("body", ""),
+        }
+        if reveal:
+            entry["url"] = c.get("html_url")
+        out.append(entry)
+    return {"success": True, "issue_number": issue_number, "comments": out}
+
+
+@mcp.tool()
+def gitea_create_issue_comment(
+    issue_number: int,
+    body: str,
+    remote: str = "dadeschools",
+    host: str | None = None,
+    org: str | None = None,
+    repo: str | None = None,
+) -> dict:
+    """Post a markdown comment to a Gitea issue's discussion thread.
+
+    Issue discussion comments are distinct from PR reviews: this posts to the
+    issue comment thread only and never submits review verdicts. The profile
+    must allow ``gitea.issue.comment`` — gated separately from the gitea.pr.*
+    review/merge operations (fail closed otherwise). The target issue is
+    always explicit; there is no inference beyond the standard remote
+    defaults used by every tool.
+
+    Normal output is LLM-safe: comment id + issue number, no endpoint URLs.
+    Set GITEA_MCP_REVEAL_ENDPOINTS=1 (admin/debug opt-in) to include the
+    comment's web link. Errors are redacted before being raised.
+
+    Args:
+        issue_number: The issue number to comment on (required).
+        body: Markdown comment body (required, non-empty).
+        remote: Known instance — 'dadeschools' or 'prgs'.
+        host: Override the Gitea host.
+        org: Override the owner/organization.
+        repo: Override the repository name.
+
+    Returns:
+        dict with 'success', 'comment_id', and 'issue_number' ('url' only
+        with the reveal opt-in); on a permission block or empty body,
+        'success'/'performed' False and 'reasons' with no API call made.
+    """
+    reasons = _issue_comment_gate("gitea.issue.comment")
+    if not (body or "").strip():
+        reasons.append("comment body must be a non-empty string")
+    if reasons:
+        return {"success": False, "performed": False,
+                "issue_number": issue_number, "reasons": reasons}
+    h, o, r = _resolve(remote, host, org, repo)
+    auth = _auth(h)
+    api = f"{repo_api_url(h, o, r)}/issues/{issue_number}/comments"
+    try:
+        with _audited("create_issue_comment", host=h, remote=remote, org=o,
+                      repo=r, issue_number=issue_number,
+                      request_metadata={"body_chars": len(body)}):
+            data = api_request("POST", api, auth, {"body": body})
+    except Exception as exc:
+        raise RuntimeError(_redact(str(exc))) from None
+    result = {"success": True, "performed": True,
+              "comment_id": data["id"], "issue_number": issue_number}
+    if _reveal_endpoints():
+        result["url"] = data.get("html_url")
+    return result
+
+
+# ── Operator guide / project skills (#128) ───────────────────────────────────
+# Read-only capability discovery for new LLM sessions: what the active
+# profile may do, how identity is verified, the non-negotiable safety rules,
+# and which project workflows ("skills") exist. Nothing here mutates state or
+# widens any permission — the guide describes the gates, it never bypasses
+# them.
+
+def _role_kind(allowed, forbidden) -> str:
+    """Classify the active profile from its normalized operations.
+
+    'author' can create PRs / push branches; 'reviewer' can approve/merge;
+    'mixed' can do both (a config smell — the reviewer-deadlock invariant
+    forbids it in v2 configs); 'limited' can do neither.
+    """
+    def can(op):
+        return gitea_config.check_operation(op, allowed, forbidden)[0]
+    review = can("gitea.pr.approve") or can("gitea.pr.merge")
+    author = can("gitea.pr.create") or can("gitea.branch.push")
+    if review and author:
+        return "mixed"
+    if review:
+        return "reviewer"
+    if author:
+        return "author"
+    return "limited"
+
+
+_HARD_STOPS = [
+    "No self-review and no self-merge: the authenticated user must differ "
+    "from the PR author for review/approve/merge.",
+    "No tags or releases without an explicit operator instruction.",
+    "Never print token values, keychain IDs, passwords, or raw service "
+    "URLs in normal output.",
+    "No production access or production mutations.",
+    "No force-merge and no bypassing of merge gates; Gitea's own "
+    "mergeable signal is honoured, never overridden.",
+    "Do not rewrite the live profiles config; config changes are "
+    "operator-owned.",
+]
+
+_GUIDE_RULES = {
+    "hard_stops": _HARD_STOPS,
+    "fail_closed": (
+        "Every gate fails closed: unknown/disabled profiles, unknown "
+        "operations, empty allowed-operation lists, unresolved identity, "
+        "and unparseable config all deny the action instead of guessing. "
+        "Disabled profiles/services are never silently substituted."),
+    "head_sha_pinning": (
+        "Before reviewing or merging, record the PR head SHA and pass it as "
+        "expected_head_sha; if the head moves between review and merge, the "
+        "tool refuses and the review must be redone."),
+    "merge_confirmation": (
+        "gitea_merge_pr requires confirmation to equal 'MERGE PR <n>' "
+        "exactly (e.g. 'MERGE PR 42'); without it no API call is made. "
+        "Merge only when the operator has explicitly authorized it."),
+    "redaction": [
+        "Normal output contains no endpoint URLs, keychain IDs, or token "
+        "values; auth is reported as type/status only.",
+        "GITEA_MCP_REVEAL_ENDPOINTS=1 is the local admin/debug opt-in for "
+        "web links and endpoint names; it never reveals token values.",
+        "Errors are redacted before being surfaced.",
+    ],
+    "separation": (
+        "Author, reviewer, and merger are separate identities. An author "
+        "profile creates branches/commits/PRs and must never "
+        "review/approve/merge its own work; a reviewer/merger profile "
+        "reviews and merges and must never create PRs or push branches "
+        "(reviewer-deadlock invariant). Issue discussion comments "
+        "(gitea.issue.comment) are gated separately from PR reviews "
+        "(gitea.pr.*)."),
+    "profile_switching": [
+        "The active profile is selected via GITEA_MCP_PROFILE (with GITEA_MCP_CONFIG pointing at the config path).",
+        "By default, static-profile mode is active: changing local environment variables does not dynamically update the already-connected MCP server process.",
+        "If runtime profile switching is explicitly enabled in the config (allow_runtime_switching: true), use gitea_activate_profile to switch profiles in-place.",
+        "If switching is disabled, you must change the launcher configuration/environment (dual-namespace) and reconnect/restart the MCP session.",
+        "After any profile switch or startup, you must verify the new runtime identity with a fresh gitea_whoami call before taking action."
+    ],
+    "identity_verification": [
+        "Call gitea_whoami with an explicit remote first; confirm the "
+        "authenticated username and profile match the role you were asked "
+        "to perform.",
+        "If the username, profile, or allowed operations do not match the "
+        "task, STOP and report instead of proceeding.",
+        "Runtime identity (whoami) is the source of truth; config-declared "
+        "roles are metadata only.",
+    ],
+}
+
+_COMMON_WORKFLOWS = [
+    "issue authoring: verify identity, create/claim the issue, keep scope "
+    "explicit (remote/org/repo).",
+    "implementation: claim issue, branch from fresh master, implement only "
+    "the issue scope, test, open a PR referencing the issue, stop.",
+    "PR review: verify reviewer identity, pin the head SHA, validate "
+    "independently, post a verdict; never review your own work.",
+    "PR merge: reviewer identity + eligibility check + pinned head + "
+    "explicit 'MERGE PR <n>' confirmation, only with operator "
+    "authorization.",
+]
+
+# Skill registry (#128). status: 'available' = backed by tools in this
+# server; 'designed-not-implemented' = design exists but no MCP tools yet
+# (listed rather than omitted so sessions know the boundary); 'operator-only'
+# = never performed by an LLM session.
+_PROJECT_SKILLS = {
+    "gitea-issue-authoring": {
+        "description": "Create, view, label, claim, and close Gitea issues.",
+        "when_to_use": "Filing new work, updating issue state, claiming an "
+                       "issue before implementation (gitea_mark_issue).",
+        "required_operations": ["gitea.read"],
+        "status": "available",
+        "notes": "Always pass remote/org/repo explicitly.",
+        "steps": [
+            "Verify identity with gitea_whoami (explicit remote).",
+            "Check the issue queue with gitea_list_issues.",
+            "Create with gitea_create_issue or claim with gitea_mark_issue "
+            "action='start'.",
+            "Keep issue bodies free of secrets, tokens, and raw service "
+            "URLs.",
+            "Release the claim (action='done') or close when finished.",
+        ],
+    },
+    "gitea-pr-creation": {
+        "description": "Author a feature branch and open a pull request.",
+        "when_to_use": "After implementing a claimed issue on a feature "
+                       "branch; author profiles only.",
+        "required_operations": ["gitea.pr.create"],
+        "status": "available",
+        "steps": [
+            "Branch from fresh master (git pull first).",
+            "Implement only the claimed issue's scope; stage files "
+            "explicitly.",
+            "Run targeted tests, the full suite, py_compile, git diff "
+            "--check, and a secret sweep before committing.",
+            "Open the PR with gitea_create_pr referencing the issue "
+            "('Closes #<n>').",
+            "Stop: do not review or merge your own PR.",
+        ],
+    },
+    "gitea-pr-review": {
+        "description": "Independently review a pull request and post a "
+                       "verdict.",
+        "when_to_use": "Reviewer profile asked to evaluate someone else's "
+                       "PR.",
+        "required_operations": ["gitea.pr.review"],
+        "status": "available",
+        "steps": [
+            "Verify reviewer identity with gitea_whoami; the PR author "
+            "must be a different user.",
+            "Pin the PR head SHA (gitea_view_pr) before validating.",
+            "Validate independently: scope vs the linked issue, tests, "
+            "diff check, secret sweep.",
+            "Post the verdict with gitea_review_pr / "
+            "gitea_submit_pr_review.",
+            "Do not merge unless the operator explicitly authorizes it.",
+        ],
+    },
+    "gitea-pr-merge": {
+        "description": "Gated merge of an approved pull request.",
+        "when_to_use": "Reviewer/merger profile with explicit operator "
+                       "authorization to merge.",
+        "required_operations": ["gitea.pr.merge"],
+        "status": "available",
+        "steps": [
+            "Confirm operator authorization for this specific merge.",
+            "Run gitea_check_pr_eligibility action='merge' and resolve "
+            "every reason it reports.",
+            "Call gitea_merge_pr with expected_head_sha pinned and "
+            "confirmation 'MERGE PR <n>'.",
+            "Confirm linked issues auto-closed and the in-progress label "
+            "was released.",
+        ],
+    },
+    "gitea-issue-comments": {
+        "description": "Read and post issue discussion comments (distinct "
+                       "from PR reviews).",
+        "when_to_use": "Design discussions, review notes on issues, "
+                       "decision records.",
+        "required_operations": ["gitea.issue.comment"],
+        "status": "available",
+        "notes": "Listing needs only gitea.read; posting needs "
+                 "gitea.issue.comment, gated separately from gitea.pr.*.",
+        "steps": [
+            "List with gitea_list_issue_comments (explicit issue number).",
+            "Post with gitea_create_issue_comment; markdown body, no "
+            "secrets or raw URLs.",
+            "Never use PR review tools for issue discussion or vice "
+            "versa.",
+        ],
+    },
+    "profile-switching": {
+        "description": "Change the active MCP identity between author and "
+                       "reviewer profiles.",
+        "when_to_use": "A task requires a role the current profile "
+                       "forbids (e.g. moving from authoring to review).",
+        "required_operations": [],
+        "status": "available",
+        "steps": [
+            "Check profile mode using gitea_get_runtime_context.",
+            "If dynamic-profile mode is enabled (allow_runtime_switching: true), "
+            "call gitea_activate_profile to switch in-place.",
+            "If static-profile mode (default), ask the operator to update GITEA_MCP_PROFILE "
+            "in the launcher environment and reconnect/restart the MCP server.",
+            "Immediately verify the new identity with a fresh gitea_whoami call before taking action.",
+            "If identity does not match the expected role, STOP.",
+        ],
+    },
+    "redaction-security-review": {
+        "description": "Sweep changes and tool output for secrets, "
+                       "keychain IDs, token values, and raw service URLs.",
+        "when_to_use": "Before every commit/PR and when reviewing any "
+                       "diff.",
+        "required_operations": ["gitea.read"],
+        "status": "available",
+        "steps": [
+            "Run git diff --check for whitespace damage.",
+            "Grep the diff for token/password/secret/keychain patterns; "
+            "only synthetic fixtures may match.",
+            "Confirm normal tool output contains no endpoint URLs or "
+            "keychain IDs (reveal opt-in excepted).",
+            "Confirm no live config or private machine paths are being "
+            "committed.",
+        ],
+    },
+    "jenkins-readonly": {
+        "description": "Read-only Jenkins CI inspection (jobs, builds, "
+                       "logs).",
+        "when_to_use": "Checking CI state once Jenkins MCP tools exist.",
+        "required_operations": ["jenkins.read"],
+        "status": "designed-not-implemented",
+        "notes": "Design exists (issues #72/#77); no Jenkins MCP server is "
+                 "connected yet. Report SKIPPED rather than substituting "
+                 "shell or direct API calls.",
+        "steps": [
+            "Confirm a Jenkins MCP server is connected; if not, report "
+            "SKIPPED.",
+            "Use read-only operations only; never trigger, cancel, or "
+            "configure builds.",
+        ],
+    },
+    "glitchtip-readonly": {
+        "description": "Read-only GlitchTip error/event inspection.",
+        "when_to_use": "Investigating reported errors once GlitchTip MCP "
+                       "tools exist.",
+        "required_operations": ["glitchtip.read"],
+        "status": "designed-not-implemented",
+        "notes": "Design exists (issue #73); no GlitchTip MCP server is "
+                 "connected yet. Report SKIPPED rather than substituting "
+                 "shell or direct API calls.",
+        "steps": [
+            "Confirm a GlitchTip MCP server is connected; if not, report "
+            "SKIPPED.",
+            "Use read-only operations only; never mutate issues or "
+            "settings.",
+        ],
+    },
+    "release-operator": {
+        "description": "Release, tag, and version workflows.",
+        "when_to_use": "Never by an LLM session on its own: releases and "
+                       "tags are operator-owned.",
+        "required_operations": [],
+        "status": "operator-only",
+        "notes": "See the release SOP docs. Hard stop: no tags or "
+                 "releases without an explicit operator instruction.",
+        "steps": [
+            "Stop and hand off to the operator; do not create tags or "
+            "releases.",
+        ],
+    },
+}
+
+
+@mcp.tool()
+def mcp_get_control_plane_guide(
+    remote: str = "dadeschools",
+    host: str | None = None,
+) -> dict:
+    """Structured operator guide for the current Gitea MCP session (#128).
+
+    Read-only. Call this first in a new session: it reports the active
+    profile, the authenticated identity (fail-soft), what this profile may
+    and may not do, and the non-negotiable workflow rules (hard stops,
+    fail-closed behavior, head-SHA pinning, merge confirmation, redaction,
+    author/reviewer separation, profile switching). Guidance is
+    profile-aware; if identity cannot be resolved it instructs the session
+    to STOP.
+
+    Args:
+        remote: Known instance — 'dadeschools' or 'prgs'.
+        host: Override the Gitea host.
+
+    Returns:
+        dict with 'read_only', 'remote', 'profile' (name, operations,
+        role_kind), 'identity' (username/status/instruction; 'server' only
+        with the reveal opt-in), 'guidance' (profile-specific), 'rules',
+        'workflows', and 'skills_tool'. Never secrets.
+    """
+    h, _, _ = _resolve(remote, host, None, None)
+    profile = get_profile()
+    allowed = profile["allowed_operations"]
+    forbidden = profile["forbidden_operations"]
+    role = _role_kind(allowed, forbidden)
+    username = _authenticated_username(h)
+
+    identity = {
+        "authenticated_username": username,
+        "remote": remote,
+        "status": "verified" if username else "unresolved",
+        "instruction": (
+            "Identity verified — confirm it matches the role this task "
+            "requires before acting."
+            if username else
+            "STOP: the authenticated identity could not be resolved. Do "
+            "not perform any mutating operation; report to the operator "
+            "and wait."),
+    }
+    if _reveal_endpoints():
+        identity["server"] = h
+
+    guidance = []
+    if not username:
+        guidance.append(
+            "STOP: identity unresolved — no mutating operations until the "
+            "operator fixes credentials/profile and gitea_whoami verifies.")
+    if role == "author":
+        guidance.append(
+            "Author profile: creating branches, commits, issues, and PRs "
+            "is allowed; review, approve, and merge are forbidden for this "
+            "profile — never attempt them, and never review or merge your "
+            "own PR from any profile.")
+    elif role == "reviewer":
+        guidance.append(
+            "Reviewer profile: review/approve/merge may proceed ONLY after "
+            "gitea_check_pr_eligibility passes and the PR head SHA is "
+            "pinned (expected_head_sha); the PR author must be a different "
+            "user, and merging additionally requires explicit operator "
+            "authorization plus the 'MERGE PR <n>' confirmation.")
+    elif role == "mixed":
+        guidance.append(
+            "WARNING: this profile allows both authoring and "
+            "review/merge, which defeats two-party review. Treat it as "
+            "misconfigured: STOP and report to the operator before any "
+            "review or merge.")
+    else:
+        guidance.append(
+            "Limited profile: no authoring and no review/merge "
+            "operations are allowed. Read-only work only; anything else "
+            "fails closed.")
+
+    return {
+        "read_only": True,
+        "remote": remote,
+        "profile": {
+            "name": profile["profile_name"],
+            "allowed_operations": allowed,
+            "forbidden_operations": forbidden,
+            "role_kind": role,
+        },
+        "identity": identity,
+        "guidance": guidance,
+        "rules": _GUIDE_RULES,
+        "workflows": _COMMON_WORKFLOWS,
+        "skills_tool": "mcp_list_project_skills",
+    }
+
+
+@mcp.tool()
+def mcp_list_project_skills() -> dict:
+    """List the project's workflow skills and when to use them (#128).
+
+    Read-only; makes no API calls. Each skill reports its name,
+    description, when-to-use guidance, required operations, status
+    ('available', 'designed-not-implemented', or 'operator-only'), and
+    whether the current profile's operations permit it. Use
+    mcp_get_skill_guide(name) for the step-by-step guide.
+
+    Returns:
+        dict with 'read_only', 'count', and 'skills' (list). Never secrets.
+    """
+    profile = get_profile()
+    allowed = profile["allowed_operations"]
+    forbidden = profile["forbidden_operations"]
+    skills = []
+    for name, meta in _PROJECT_SKILLS.items():
+        ops = meta["required_operations"]
+        available = all(
+            gitea_config.check_operation(op, allowed, forbidden)[0]
+            for op in ops
+        ) if ops else True
+        entry = {
+            "name": name,
+            "description": meta["description"],
+            "when_to_use": meta["when_to_use"],
+            "required_operations": ops,
+            "status": meta["status"],
+            "available_to_current_profile": (
+                available and meta["status"] == "available"),
+        }
+        if meta.get("notes"):
+            entry["notes"] = meta["notes"]
+        skills.append(entry)
+    return {"read_only": True, "count": len(skills), "skills": skills}
+
+
+@mcp.tool()
+def mcp_get_skill_guide(skill_name: str) -> dict:
+    """Step-by-step guide for one named project skill (#128).
+
+    Read-only; makes no API calls. Unknown skill names fail closed with
+    the list of valid names instead of guessing.
+
+    Args:
+        skill_name: A name from mcp_list_project_skills (case-insensitive).
+
+    Returns:
+        dict with 'success', 'skill' metadata, and 'steps'; on an unknown
+        name, 'success' False with 'reasons' and 'valid_skills'.
+    """
+    key = (skill_name or "").strip().lower()
+    meta = _PROJECT_SKILLS.get(key)
+    if meta is None:
+        return {
+            "success": False,
+            "reasons": [f"unknown skill '{skill_name}' (fail closed)"],
+            "valid_skills": sorted(_PROJECT_SKILLS),
+        }
+    skill = {
+        "name": key,
+        "description": meta["description"],
+        "when_to_use": meta["when_to_use"],
+        "required_operations": meta["required_operations"],
+        "status": meta["status"],
+    }
+    if meta.get("notes"):
+        skill["notes"] = meta["notes"]
+    return {"success": True, "skill": skill, "steps": list(meta["steps"])}
+
+
 @mcp.tool()
 def gitea_whoami(
     remote: str = "dadeschools",
@@ -1538,6 +2192,306 @@ def gitea_get_profile(
     return result
 
 
+@mcp.tool()
+def gitea_get_runtime_context(
+    remote: str = "dadeschools",
+    host: str | None = None,
+) -> dict:
+    """Read-only: explicit visibility into active profile, configuration model, and eligibility.
+
+    Reports config model shape, profile mode (static vs dynamic), and detailed blocks.
+
+    Args:
+        remote: Known instance — 'dadeschools' or 'prgs'.
+        host: Override the Gitea host.
+    """
+    profile = get_profile()
+    config = gitea_config.load_config()
+    reveal = _reveal_endpoints()
+
+    # Determine config model/version
+    if config is None:
+        config_model = "env-only"
+    elif config.get("version") == 1:
+        config_model = "v1"
+    elif config.get("version") == 2:
+        if "contexts" in config or config.get("shape") == "contexts":
+            config_model = "v2-contexts"
+        else:
+            config_model = "v2-environments"
+    else:
+        config_model = f"unknown-version-{config.get('version')}"
+
+    # Determine profile source
+    if os.environ.get("GITEA_PROFILE_NAME"):
+        profile_source = "env var"
+    elif gitea_config.selected_profile_name():
+        profile_source = "config file profile"
+    else:
+        profile_source = "default"
+
+    h = host or (REMOTES.get(remote, {}).get("host") if remote in REMOTES else None)
+    username = _authenticated_username(h) if h else None
+
+    switching = gitea_config.is_runtime_switching_enabled()
+    profile_mode = "dynamic-profile" if switching else "static-profile"
+
+    # Evaluate review/merge eligibility
+    allowed = profile["allowed_operations"] or []
+    forbidden = profile["forbidden_operations"] or []
+
+    # Check approve
+    approve_ok, _ = gitea_config.check_operation("approve", allowed, forbidden)
+    # Check merge
+    merge_ok, _ = gitea_config.check_operation("merge", allowed, forbidden)
+
+    review_merge_allowed = False
+    blocked_reasons = []
+    suggested_fix = "none"
+
+    if not username:
+        blocked_reasons.append("Authenticated identity is unresolved. Gitea credentials are missing or invalid.")
+        suggested_fix = "operator action"
+    elif not (approve_ok or merge_ok):
+        blocked_reasons.append(
+            f"Active profile '{profile['profile_name']}' does not permit review or merge operations."
+        )
+        if switching:
+            suggested_fix = "profile switch"
+        else:
+            suggested_fix = "reviewer namespace"
+    else:
+        review_merge_allowed = True
+
+    # Note that self-review and self-merge are blocked regardless of profile roles
+    blocked_reasons.append(
+        "Note: self-review and self-merge are always blocked at runtime for any PR authored by the active user."
+    )
+
+    safe_next_action = "None; ready for operations."
+    if suggested_fix == "operator action":
+        safe_next_action = f"Ask the operator to configure valid credentials/token for profile '{profile['profile_name']}'."
+    elif suggested_fix == "profile switch":
+        safe_next_action = "Switch to a reviewer profile by calling gitea_activate_profile with a reviewer profile."
+    elif suggested_fix == "reviewer namespace":
+        safe_next_action = (
+            "Switch to the reviewer MCP session (e.g. gitea-reviewer) which has reviewer permissions configured, "
+            "or ask the operator to update GITEA_MCP_PROFILE to a reviewer profile."
+        )
+
+    result = {
+        "active_profile": profile["profile_name"],
+        "authenticated_username": username,
+        "remote": remote if remote in REMOTES else None,
+        "config_model": config_model,
+        "profile_source": profile_source,
+        "allowed_operations": allowed,
+        "forbidden_operations": forbidden,
+        "runtime_switching_supported": switching,
+        "profile_mode": profile_mode,
+        "review_merge_allowed": review_merge_allowed,
+        "review_merge_blocked_reasons": blocked_reasons,
+        "suggested_fix": suggested_fix,
+        "safe_next_action": safe_next_action,
+    }
+
+    if reveal and h:
+        result["server"] = f"https://{h}"
+
+    return result
+
+
+@mcp.tool()
+def gitea_list_profiles() -> dict:
+    """Read-only: list all Gitea MCP profiles with redacted metadata.
+
+    Exposes names, role kinds, enabled state, allowed/forbidden operations, and active status.
+    Token values, keychain IDs, and raw URLs are hidden unless GITEA_MCP_REVEAL_ENDPOINTS=1 is enabled.
+    """
+    config = gitea_config.load_config()
+    reveal = _reveal_endpoints()
+    active_name = gitea_config.selected_profile_name() or get_profile()["profile_name"]
+
+    profiles_out = []
+
+    if config is None:
+        # Env-only: return the active profile
+        p = get_profile()
+        role = _role_kind(p["allowed_operations"], p["forbidden_operations"])
+        h = REMOTES.get("dadeschools", {}).get("host")  # default host
+        username = _authenticated_username(h) if h else None
+        
+        prof = {
+            "name": p["profile_name"],
+            "role_kind": role,
+            "allowed_operations": p["allowed_operations"],
+            "forbidden_operations": p["forbidden_operations"],
+            "identity_status": "verified" if username else "unresolved",
+            "is_active": True,
+            "enabled": True,
+        }
+        if reveal:
+            prof["token_source_name"] = p["token_source_name"]
+            prof["base_url"] = p["base_url"]
+        profiles_out.append(prof)
+    else:
+        # Load from config profiles
+        profiles_dict = config.get("profiles") or {}
+        unavailable_dict = config.get("unavailable") or {}
+        audit_only_profiles = config.get("audit_only_profiles") or {}
+
+        # First, process available profiles
+        for name, p in profiles_dict.items():
+            role = _role_kind(p.get("allowed_operations", []), p.get("forbidden_operations", []))
+            is_active = (name == active_name)
+            
+            # Identity status lookup
+            if is_active:
+                h = REMOTES.get("dadeschools", {}).get("host")  # default host
+                username = _authenticated_username(h) if h else None
+                identity_status = "verified" if username else "unresolved"
+            else:
+                # Safely resolve if credentials are present without networking
+                try:
+                    tok = gitea_config.resolve_token(p)
+                    identity_status = "credentials present" if tok else "missing credentials"
+                except Exception:
+                    identity_status = "missing credentials"
+
+            prof = {
+                "name": name,
+                "role_kind": role,
+                "allowed_operations": p.get("allowed_operations", []),
+                "forbidden_operations": p.get("forbidden_operations", []),
+                "identity_status": identity_status,
+                "is_active": is_active,
+                "enabled": p.get("enabled", True),
+            }
+            if reveal:
+                if isinstance(p.get("auth"), dict):
+                    prof["auth"] = p["auth"]
+                prof["base_url"] = p.get("base_url")
+            else:
+                if isinstance(p.get("auth"), dict):
+                    prof["auth"] = {k: ("<redacted>" if k != "type" else v) for k, v in p["auth"].items()}
+                prof["base_url"] = "<redacted>"
+            profiles_out.append(prof)
+
+        # Process unavailable/disabled/audit-only profiles
+        for name, p in audit_only_profiles.items():
+            role = _role_kind(p.get("allowed_operations", []), p.get("forbidden_operations", []))
+            is_active = (name == active_name)
+            prof = {
+                "name": name,
+                "role_kind": role,
+                "allowed_operations": p.get("allowed_operations", []),
+                "forbidden_operations": p.get("forbidden_operations", []),
+                "identity_status": "unavailable (disabled)",
+                "is_active": is_active,
+                "enabled": p.get("enabled", True),
+                "unavailable_reason": p.get("_unavailable_reason"),
+            }
+            if reveal:
+                if isinstance(p.get("auth"), dict):
+                    prof["auth"] = p["auth"]
+                prof["base_url"] = p.get("base_url")
+            else:
+                if isinstance(p.get("auth"), dict):
+                    prof["auth"] = {k: ("<redacted>" if k != "type" else v) for k, v in p["auth"].items()}
+                prof["base_url"] = "<redacted>"
+            profiles_out.append(prof)
+
+        # Handle unavailable mappings that are not in audit_only
+        for name, reason in unavailable_dict.items():
+            if not any(x["name"] == name for x in profiles_out):
+                profiles_out.append({
+                    "name": name,
+                    "role_kind": "limited",
+                    "allowed_operations": [],
+                    "forbidden_operations": [],
+                    "identity_status": "unavailable",
+                    "is_active": (name == active_name),
+                    "enabled": False,
+                    "unavailable_reason": reason,
+                })
+
+    return {"profiles": profiles_out}
+
+
+@mcp.tool()
+def gitea_activate_profile(
+    profile_name: str,
+    remote: str = "dadeschools",
+    host: str | None = None,
+) -> dict:
+    """Gated profile activation. Switch the active profile in-place for this runtime session.
+
+    Only allowed if "allow_runtime_switching": true is explicitly configured.
+
+    Args:
+        profile_name: Profile to activate.
+        remote: Known instance — 'dadeschools' or 'prgs'.
+        host: Override the Gitea host.
+    """
+    if not gitea_config.is_runtime_switching_enabled():
+        return {
+            "success": False,
+            "message": (
+                "Runtime profile switching is disabled in this configuration. Static profile mode is active. "
+                "To enable switching, set 'allow_runtime_switching': true in the config rules."
+            )
+        }
+
+    config = gitea_config.load_config()
+    if not config:
+        return {
+            "success": False,
+            "message": "No profiles configuration file is loaded. Switching is not supported in env-only mode."
+        }
+
+    profiles_dict = config.get("profiles") or {}
+    if profile_name not in profiles_dict:
+        return {
+            "success": False,
+            "message": f"Profile '{profile_name}' not found in loaded config."
+        }
+
+    h = host or (REMOTES.get(remote, {}).get("host") if remote in REMOTES else None)
+
+    # 1. Record before state
+    before_profile = get_profile()["profile_name"]
+    before_identity = _authenticated_username(h) if h else None
+
+    # 2. Perform switch
+    gitea_config._active_profile_override = profile_name
+
+    # 3. Clear identity cache to force a fresh verification
+    if h:
+        _IDENTITY_CACHE.pop(h, None)
+    
+    # 4. Resolve fresh identity
+    after_profile = get_profile()["profile_name"]
+    after_identity = _authenticated_username(h) if h else None
+
+    # 5. Audit the switch if auditing is on
+    _audit(
+        "activate_profile",
+        host=h,
+        remote=remote,
+        result={"success": True, "before": before_profile, "after": after_profile},
+        username=after_identity,
+    )
+
+    return {
+        "success": True,
+        "message": f"Successfully activated profile '{profile_name}' (fresh identity verification complete).",
+        "before_profile": before_profile,
+        "before_identity": before_identity,
+        "after_profile": after_profile,
+        "after_identity": after_identity,
+    }
+
+
 @mcp.tool()
 def gitea_audit_config() -> dict:
     """Audit the configured profiles/services: enabled state, no secrets.

tests/test_mcp_server.py

@@ -31,6 +31,8 @@ from mcp_server import (  # noqa: E402
     gitea_get_profile,
     gitea_check_pr_eligibility,
     gitea_submit_pr_review,
+    gitea_list_issue_comments,
+    gitea_create_issue_comment,
 )
 from gitea_auth import get_profile  # noqa: E402
 
@@ -1903,3 +1905,199 @@ class TestEndpointRedaction(unittest.TestCase):
             from mcp_server import gitea_audit_config
             result = gitea_audit_config()
         self.assertFalse(result["configured"])
+
+
+# ---------------------------------------------------------------------------
+# Issue comment tools (#126)
+# ---------------------------------------------------------------------------
+class TestIssueCommentTools(unittest.TestCase):
+    """gitea_list_issue_comments / gitea_create_issue_comment (#126).
+
+    Issue discussion comments are distinct from PR reviews: they hit the
+    /issues/{n}/comments endpoint, are gated on gitea.read (list) and
+    gitea.issue.comment (create) — never on the gitea.pr.* review/merge
+    family — and their normal output is LLM-safe (no endpoint URLs; the
+    GITEA_MCP_REVEAL_ENDPOINTS opt-in restores links for local diagnostics).
+    """
+
+    AUTHOR_ENV = {
+        "GITEA_PROFILE_NAME": "gitea-author",
+        "GITEA_ALLOWED_OPERATIONS": "gitea.read,gitea.issue.comment",
+    }
+
+    @staticmethod
+    def _comment(cid=101, login="alice", body="hello world"):
+        return {
+            "id": cid,
+            "user": {"login": login},
+            "body": body,
+            "created_at": "2026-07-03T00:00:00Z",
+            "updated_at": "2026-07-03T01:00:00Z",
+            "html_url": (
+                "https://gitea.example.com/o/r/issues/9#issuecomment-%d" % cid
+            ),
+        }
+
+    # -- list ----------------------------------------------------------------
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_lists_comments(self, _auth, mock_api):
+        mock_api.return_value = [self._comment(101), self._comment(102, "bob")]
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            result = gitea_list_issue_comments(issue_number=9, remote="prgs")
+        self.assertTrue(result["success"])
+        self.assertEqual(result["issue_number"], 9)
+        self.assertEqual(len(result["comments"]), 2)
+        first = result["comments"][0]
+        self.assertEqual(first["id"], 101)
+        self.assertEqual(first["author"], "alice")
+        self.assertEqual(first["body"], "hello world")
+        self.assertEqual(first["created_at"], "2026-07-03T00:00:00Z")
+        self.assertEqual(first["updated_at"], "2026-07-03T01:00:00Z")
+        url = mock_api.call_args[0][1]
+        self.assertIn("/issues/9/comments", url)
+        self.assertEqual(mock_api.call_args[0][0], "GET")
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_list_output_has_no_urls_by_default(self, _auth, mock_api):
+        mock_api.return_value = [self._comment()]
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            result = gitea_list_issue_comments(issue_number=9, remote="prgs")
+        blob = json.dumps(result)
+        self.assertNotIn("https://", blob)
+        self.assertNotIn("http://", blob)
+        self.assertNotIn("url", blob)
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_list_reveal_opt_in_includes_url(self, _auth, mock_api):
+        mock_api.return_value = [self._comment()]
+        env = dict(self.AUTHOR_ENV, GITEA_MCP_REVEAL_ENDPOINTS="1")
+        with patch.dict(os.environ, env, clear=True):
+            result = gitea_list_issue_comments(issue_number=9, remote="prgs")
+        self.assertIn("issuecomment-101", result["comments"][0]["url"])
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_list_blocked_without_read_permission(self, _auth, mock_api):
+        env = {"GITEA_PROFILE_NAME": "gitea-writer-only",
+               "GITEA_ALLOWED_OPERATIONS": "gitea.issue.comment"}
+        with patch.dict(os.environ, env, clear=True):
+            result = gitea_list_issue_comments(issue_number=9, remote="prgs")
+        self.assertFalse(result["success"])
+        self.assertTrue(result["reasons"])
+        mock_api.assert_not_called()
+
+    def test_list_unknown_remote_raises(self):
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            with self.assertRaises(ValueError):
+                gitea_list_issue_comments(issue_number=9, remote="nope")
+
+    # -- create ----------------------------------------------------------------
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_creates_comment(self, _auth, mock_api):
+        mock_api.return_value = self._comment(555, "gitea-author", "posted")
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            result = gitea_create_issue_comment(
+                issue_number=9, body="posted", remote="prgs")
+        self.assertTrue(result["success"])
+        self.assertEqual(result["comment_id"], 555)
+        self.assertEqual(result["issue_number"], 9)
+        self.assertEqual(mock_api.call_args[0][0], "POST")
+        url = mock_api.call_args[0][1]
+        self.assertIn("/issues/9/comments", url)
+        self.assertIn("gitea.prgs.cc", url)
+        self.assertIn("Scaled-Tech-Consulting", url)
+        self.assertEqual(mock_api.call_args[0][3], {"body": "posted"})
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_create_output_has_no_urls_by_default(self, _auth, mock_api):
+        mock_api.return_value = self._comment(555)
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            result = gitea_create_issue_comment(
+                issue_number=9, body="posted", remote="prgs")
+        blob = json.dumps(result)
+        self.assertNotIn("https://", blob)
+        self.assertNotIn("http://", blob)
+        self.assertNotIn("url", blob)
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_create_reveal_opt_in_includes_url(self, _auth, mock_api):
+        mock_api.return_value = self._comment(555)
+        env = dict(self.AUTHOR_ENV, GITEA_MCP_REVEAL_ENDPOINTS="1")
+        with patch.dict(os.environ, env, clear=True):
+            result = gitea_create_issue_comment(
+                issue_number=9, body="posted", remote="prgs")
+        self.assertIn("issuecomment-555", result["url"])
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_review_permissions_do_not_grant_issue_comments(self, _auth, mock_api):
+        env = {"GITEA_PROFILE_NAME": "gitea-reviewer",
+               "GITEA_ALLOWED_OPERATIONS":
+                   "gitea.read,gitea.pr.review,gitea.pr.comment,"
+                   "gitea.pr.approve,gitea.pr.merge"}
+        with patch.dict(os.environ, env, clear=True):
+            result = gitea_create_issue_comment(
+                issue_number=9, body="posted", remote="prgs")
+        self.assertFalse(result["success"])
+        self.assertFalse(result["performed"])
+        self.assertTrue(result["reasons"])
+        mock_api.assert_not_called()
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_create_forbidden_overrides_allowed(self, _auth, mock_api):
+        env = {"GITEA_PROFILE_NAME": "gitea-author",
+               "GITEA_ALLOWED_OPERATIONS": "gitea.read,gitea.issue.comment",
+               "GITEA_FORBIDDEN_OPERATIONS": "gitea.issue.comment"}
+        with patch.dict(os.environ, env, clear=True):
+            result = gitea_create_issue_comment(
+                issue_number=9, body="posted", remote="prgs")
+        self.assertFalse(result["success"])
+        mock_api.assert_not_called()
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_create_empty_body_blocked(self, _auth, mock_api):
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            result = gitea_create_issue_comment(
+                issue_number=9, body="   ", remote="prgs")
+        self.assertFalse(result["success"])
+        mock_api.assert_not_called()
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_create_missing_issue_error_is_redacted(self, _auth, mock_api):
+        mock_api.side_effect = RuntimeError(
+            "Gitea API error 404 for issue (auth was token abc123secret)")
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            with self.assertRaises(RuntimeError) as cm:
+                gitea_create_issue_comment(
+                    issue_number=99999, body="posted", remote="prgs")
+        msg = str(cm.exception)
+        self.assertNotIn("abc123secret", msg)
+        self.assertIn("404", msg)
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_create_never_touches_review_endpoints(self, _auth, mock_api):
+        mock_api.return_value = self._comment(555)
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            gitea_create_issue_comment(
+                issue_number=9, body="posted", remote="prgs")
+        for call in mock_api.call_args_list:
+            self.assertNotIn("reviews", call[0][1])
+            self.assertNotIn("/pulls/", call[0][1])
+
+    def test_create_unknown_remote_raises(self):
+        with patch.dict(os.environ, self.AUTHOR_ENV, clear=True):
+            with self.assertRaises(ValueError):
+                gitea_create_issue_comment(
+                    issue_number=9, body="x", remote="nope")

tests/test_operator_guide.py

@@ -0,0 +1,232 @@
+"""Tests for the operator guide / project skills MCP tools (#128).
+
+Read-only capability-discovery tools: mcp_get_control_plane_guide,
+mcp_list_project_skills, mcp_get_skill_guide. Each is tested by calling the
+underlying function directly with mocked API responses.
+"""
+import json
+import os
+import sys
+import unittest
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import mcp_server  # noqa: E402
+from mcp_server import (  # noqa: E402
+    mcp_get_control_plane_guide,
+    mcp_list_project_skills,
+    mcp_get_skill_guide,
+)
+
+FAKE_AUTH = "Basic dGVzdDp0ZXN0"
+
+AUTHOR_ENV = {
+    "GITEA_PROFILE_NAME": "author-test",
+    "GITEA_ALLOWED_OPERATIONS":
+        "gitea.read,gitea.repo.commit,gitea.branch.create,"
+        "gitea.branch.push,gitea.pr.create,gitea.pr.comment",
+    "GITEA_FORBIDDEN_OPERATIONS": "gitea.pr.approve,gitea.pr.merge",
+}
+
+REVIEWER_ENV = {
+    "GITEA_PROFILE_NAME": "reviewer-test",
+    "GITEA_ALLOWED_OPERATIONS":
+        "gitea.read,gitea.pr.review,gitea.pr.comment,gitea.pr.approve,"
+        "gitea.pr.request_changes,gitea.pr.merge",
+    "GITEA_FORBIDDEN_OPERATIONS": "gitea.pr.create,gitea.branch.push",
+}
+
+EXPECTED_SKILLS = [
+    "gitea-issue-authoring",
+    "gitea-pr-creation",
+    "gitea-pr-review",
+    "gitea-pr-merge",
+    "gitea-issue-comments",
+    "profile-switching",
+    "redaction-security-review",
+    "jenkins-readonly",
+    "glitchtip-readonly",
+    "release-operator",
+]
+
+
+class GuideTestBase(unittest.TestCase):
+    def setUp(self):
+        mcp_server._IDENTITY_CACHE.clear()
+
+    def tearDown(self):
+        mcp_server._IDENTITY_CACHE.clear()
+
+
+# ---------------------------------------------------------------------------
+# mcp_get_control_plane_guide
+# ---------------------------------------------------------------------------
+class TestControlPlaneGuide(GuideTestBase):
+
+    @patch("mcp_server.api_request", return_value={"login": "author-bot"})
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_author_profile_guidance(self, _auth, _api):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            g = mcp_get_control_plane_guide(remote="prgs")
+        self.assertTrue(g["read_only"])
+        self.assertEqual(g["profile"]["role_kind"], "author")
+        self.assertEqual(g["identity"]["authenticated_username"], "author-bot")
+        self.assertEqual(g["identity"]["status"], "verified")
+        blob = " ".join(g["guidance"]).lower()
+        self.assertIn("forbidden", blob)
+        self.assertIn("review", blob)
+
+    @patch("mcp_server.api_request", return_value={"login": "reviewer-bot"})
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_reviewer_profile_guidance(self, _auth, _api):
+        with patch.dict(os.environ, REVIEWER_ENV, clear=True):
+            g = mcp_get_control_plane_guide(remote="prgs")
+        self.assertEqual(g["profile"]["role_kind"], "reviewer")
+        blob = " ".join(g["guidance"]).lower()
+        self.assertIn("eligibility", blob)
+        self.assertIn("pinned", blob)
+
+    @patch("mcp_server.get_auth_header", return_value=None)
+    def test_unresolved_identity_instructs_stop(self, _auth):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            g = mcp_get_control_plane_guide(remote="prgs")
+        self.assertEqual(g["identity"]["status"], "unresolved")
+        self.assertIsNone(g["identity"]["authenticated_username"])
+        self.assertIn("STOP", g["identity"]["instruction"])
+
+    @patch("mcp_server.api_request", return_value={"login": "author-bot"})
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_guide_is_read_only(self, _auth, mock_api):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            mcp_get_control_plane_guide(remote="prgs")
+        for call in mock_api.call_args_list:
+            self.assertEqual(call[0][0], "GET")
+
+    @patch("mcp_server.api_request", return_value={"login": "author-bot"})
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_no_urls_or_keychain_ids_by_default(self, _auth, _api):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            g = mcp_get_control_plane_guide(remote="prgs")
+        blob = json.dumps(g)
+        self.assertNotIn("https://", blob)
+        self.assertNotIn("http://", blob)
+        self.assertNotIn("keychain:", blob)
+        self.assertNotIn(FAKE_AUTH, blob)
+        self.assertNotIn("server", g["identity"])
+
+    @patch("mcp_server.api_request", return_value={"login": "author-bot"})
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_reveal_opt_in_includes_server(self, _auth, _api):
+        env = dict(AUTHOR_ENV, GITEA_MCP_REVEAL_ENDPOINTS="1")
+        with patch.dict(os.environ, env, clear=True):
+            g = mcp_get_control_plane_guide(remote="prgs")
+        self.assertIn("gitea.prgs.cc", g["identity"]["server"])
+
+    @patch("mcp_server.api_request", return_value={"login": "author-bot"})
+    @patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
+    def test_rules_cover_required_topics(self, _auth, _api):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            g = mcp_get_control_plane_guide(remote="prgs")
+        rules = g["rules"]
+        for key in ("hard_stops", "fail_closed", "head_sha_pinning",
+                    "merge_confirmation", "redaction", "separation",
+                    "profile_switching", "identity_verification"):
+            self.assertIn(key, rules)
+        self.assertIn("MERGE PR", json.dumps(rules["merge_confirmation"]))
+        self.assertTrue(rules["hard_stops"])
+
+    def test_unknown_remote_raises(self):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            with self.assertRaises(ValueError):
+                mcp_get_control_plane_guide(remote="nope")
+
+
+# ---------------------------------------------------------------------------
+# mcp_list_project_skills
+# ---------------------------------------------------------------------------
+class TestProjectSkills(GuideTestBase):
+
+    @patch("mcp_server.api_request")
+    def test_registry_complete_and_no_api_calls(self, mock_api):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            r = mcp_list_project_skills()
+        self.assertTrue(r["read_only"])
+        names = [s["name"] for s in r["skills"]]
+        for expected in EXPECTED_SKILLS:
+            self.assertIn(expected, names)
+        self.assertEqual(r["count"], len(r["skills"]))
+        for s in r["skills"]:
+            self.assertTrue(s["description"])
+            self.assertTrue(s["when_to_use"])
+            self.assertIn("required_operations", s)
+            self.assertIn("status", s)
+            self.assertIn("available_to_current_profile", s)
+        mock_api.assert_not_called()
+
+    def test_profile_aware_availability(self):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            r = mcp_list_project_skills()
+        by_name = {s["name"]: s for s in r["skills"]}
+        self.assertTrue(by_name["gitea-pr-creation"]["available_to_current_profile"])
+        self.assertFalse(by_name["gitea-pr-merge"]["available_to_current_profile"])
+
+    def test_unimplemented_services_marked(self):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            r = mcp_list_project_skills()
+        by_name = {s["name"]: s for s in r["skills"]}
+        self.assertNotEqual(by_name["jenkins-readonly"]["status"], "available")
+        self.assertNotEqual(by_name["glitchtip-readonly"]["status"], "available")
+
+    def test_no_urls_in_registry(self):
+        with patch.dict(os.environ, AUTHOR_ENV, clear=True):
+            r = mcp_list_project_skills()
+        blob = json.dumps(r)
+        self.assertNotIn("https://", blob)
+        self.assertNotIn("http://", blob)
+        self.assertNotIn("keychain:", blob)
+
+
+# ---------------------------------------------------------------------------
+# mcp_get_skill_guide
+# ---------------------------------------------------------------------------
+class TestSkillGuide(GuideTestBase):
+
+    def test_known_skill_returns_steps(self):
+        with patch.dict(os.environ, REVIEWER_ENV, clear=True):
+            r = mcp_get_skill_guide("gitea-pr-merge")
+        self.assertTrue(r["success"])
+        self.assertEqual(r["skill"]["name"], "gitea-pr-merge")
+        self.assertTrue(r["steps"])
+        self.assertIn("MERGE PR", " ".join(r["steps"]))
+
+    def test_case_and_whitespace_normalized(self):
+        with patch.dict(os.environ, REVIEWER_ENV, clear=True):
+            r = mcp_get_skill_guide("  Gitea-PR-Merge ")
+        self.assertTrue(r["success"])
+
+    def test_unknown_skill_fails_closed(self):
+        with patch.dict(os.environ, REVIEWER_ENV, clear=True):
+            r = mcp_get_skill_guide("no-such-skill")
+        self.assertFalse(r["success"])
+        self.assertTrue(r["reasons"])
+        for expected in EXPECTED_SKILLS:
+            self.assertIn(expected, r["valid_skills"])
+
+    @patch("mcp_server.api_request")
+    def test_read_only_no_api_calls(self, mock_api):
+        with patch.dict(os.environ, REVIEWER_ENV, clear=True):
+            mcp_get_skill_guide("gitea-pr-review")
+        mock_api.assert_not_called()
+
+    def test_no_urls_in_skill_guides(self):
+        with patch.dict(os.environ, REVIEWER_ENV, clear=True):
+            for name in EXPECTED_SKILLS:
+                r = mcp_get_skill_guide(name)
+                blob = json.dumps(r)
+                self.assertNotIn("https://", blob)
+                self.assertNotIn("keychain:", blob)
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_runtime_clarity.py

@@ -0,0 +1,256 @@
+"""Tests for runtime context, profile activation, profile listing, and enhanced error clarity.
+
+Covers Issue #131 requirements.
+"""
+import os
+import sys
+import json
+import tempfile
+import unittest
+from unittest.mock import patch, MagicMock
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import gitea_config
+import gitea_auth
+import mcp_server
+
+CONFIG_SWITCHING_DISABLED = {
+    "version": 2,
+    "contexts": {
+        "ctx": {
+            "enabled": True,
+            "gitea": {
+                "enabled": True,
+                "base_url": "https://gitea.example.com"
+            }
+        }
+    },
+    "profiles": {
+        "author-profile": {
+            "enabled": True,
+            "context": "ctx",
+            "role": "author",
+            "username": "author-user",
+            "auth": {"type": "env", "name": "GITEA_TOKEN_AUTHOR"},
+            "allowed_operations": ["gitea.read", "gitea.pr.create", "gitea.branch.push"],
+            "forbidden_operations": ["gitea.pr.approve", "gitea.pr.merge"],
+            "execution_profile": "author-profile"
+        },
+        "reviewer-profile": {
+            "enabled": True,
+            "context": "ctx",
+            "role": "reviewer",
+            "username": "reviewer-user",
+            "auth": {"type": "env", "name": "GITEA_TOKEN_REVIEWER"},
+            "allowed_operations": ["gitea.read", "gitea.pr.approve", "gitea.pr.merge"],
+            "forbidden_operations": ["gitea.pr.create", "gitea.branch.push"],
+            "execution_profile": "reviewer-profile"
+        }
+    },
+    "rules": {
+        "allow_runtime_switching": False
+    }
+}
+
+CONFIG_SWITCHING_ENABLED = {
+    **CONFIG_SWITCHING_DISABLED,
+    "rules": {
+        "allow_runtime_switching": True
+    }
+}
+
+class TestRuntimeClarity(unittest.TestCase):
+    def setUp(self):
+        self._remotes_patch = patch.dict(mcp_server.REMOTES, {
+            "dadeschools": {"host": "gitea.example.com", "org": "Example-Org", "repo": "Example-Repo"},
+            "prgs": {"host": "gitea.example.com", "org": "Example-Org", "repo": "Example-Repo"}
+        })
+        self._remotes_patch.start()
+        mcp_server._IDENTITY_CACHE.clear()
+        gitea_config._active_profile_override = None
+        self._dir = tempfile.TemporaryDirectory()
+        self.config_path = os.path.join(self._dir.name, "profiles.json")
+        self._write_config(CONFIG_SWITCHING_DISABLED)
+
+    def tearDown(self):
+        self._remotes_patch.stop()
+        mcp_server._IDENTITY_CACHE.clear()
+        gitea_config._active_profile_override = None
+        self._dir.cleanup()
+
+    def _write_config(self, obj):
+        with open(self.config_path, "w", encoding="utf-8") as fh:
+            fh.write(json.dumps(obj))
+
+    def _env(self, profile="author-profile", reveal="0"):
+        return {
+            "GITEA_MCP_CONFIG": self.config_path,
+            "GITEA_MCP_PROFILE": profile,
+            "GITEA_MCP_REVEAL_ENDPOINTS": reveal,
+            "GITEA_TOKEN_AUTHOR": "author-pass",
+            "GITEA_TOKEN_REVIEWER": "reviewer-pass",
+        }
+
+    # -------------------------------------------------------------------------
+    # gitea_get_runtime_context
+    # -------------------------------------------------------------------------
+    @patch("mcp_server.api_request", return_value={"login": "author-user"})
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_get_runtime_context_author(self, _auth, _api):
+        with patch.dict(os.environ, self._env("author-profile"), clear=True):
+            ctx = mcp_server.gitea_get_runtime_context(remote="dadeschools")
+        self.assertEqual(ctx["active_profile"], "author-profile")
+        self.assertEqual(ctx["authenticated_username"], "author-user")
+        self.assertEqual(ctx["config_model"], "v2-contexts")
+        self.assertEqual(ctx["profile_source"], "config file profile")
+        self.assertFalse(ctx["runtime_switching_supported"])
+        self.assertEqual(ctx["profile_mode"], "static-profile")
+        self.assertFalse(ctx["review_merge_allowed"])
+        self.assertEqual(ctx["suggested_fix"], "reviewer namespace")
+        self.assertIn("does not permit review or merge", ctx["review_merge_blocked_reasons"][0])
+        self.assertIn("Switch to the reviewer MCP session", ctx["safe_next_action"])
+
+    @patch("mcp_server.api_request", return_value={"login": "reviewer-user"})
+    @patch("mcp_server.get_auth_header", return_value="token reviewer-pass")
+    def test_get_runtime_context_reviewer(self, _auth, _api):
+        with patch.dict(os.environ, self._env("reviewer-profile"), clear=True):
+            ctx = mcp_server.gitea_get_runtime_context(remote="dadeschools")
+        self.assertEqual(ctx["active_profile"], "reviewer-profile")
+        self.assertEqual(ctx["authenticated_username"], "reviewer-user")
+        self.assertTrue(ctx["review_merge_allowed"])
+        self.assertEqual(ctx["suggested_fix"], "none")
+        self.assertEqual(ctx["safe_next_action"], "None; ready for operations.")
+
+    # -------------------------------------------------------------------------
+    # gitea_list_profiles
+    # -------------------------------------------------------------------------
+    @patch("mcp_server.api_request", return_value={"login": "author-user"})
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_list_profiles_redacted_by_default(self, _auth, _api):
+        with patch.dict(os.environ, self._env("author-profile", reveal="0"), clear=True):
+            res = mcp_server.gitea_list_profiles()
+        profiles = res["profiles"]
+        self.assertEqual(len(profiles), 2)
+        
+        author_prof = next(p for p in profiles if p["name"] == "author-profile")
+        self.assertTrue(author_prof["is_active"])
+        self.assertEqual(author_prof["role_kind"], "author")
+        self.assertEqual(author_prof["auth"]["name"], "<redacted>")
+        self.assertEqual(author_prof["base_url"], "<redacted>")
+        self.assertEqual(author_prof["identity_status"], "verified")
+
+        reviewer_prof = next(p for p in profiles if p["name"] == "reviewer-profile")
+        self.assertFalse(reviewer_prof["is_active"])
+        self.assertEqual(reviewer_prof["role_kind"], "reviewer")
+        self.assertEqual(reviewer_prof["auth"]["name"], "<redacted>")
+        self.assertEqual(reviewer_prof["base_url"], "<redacted>")
+        self.assertEqual(reviewer_prof["identity_status"], "credentials present")
+
+    @patch("mcp_server.api_request", return_value={"login": "author-user"})
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_list_profiles_revealed_under_opt_in(self, _auth, _api):
+        with patch.dict(os.environ, self._env("author-profile", reveal="1"), clear=True):
+            res = mcp_server.gitea_list_profiles()
+        profiles = res["profiles"]
+        
+        author_prof = next(p for p in profiles if p["name"] == "author-profile")
+        self.assertEqual(author_prof["auth"]["name"], "GITEA_TOKEN_AUTHOR")
+        self.assertEqual(author_prof["base_url"], "https://gitea.example.com")
+
+    # -------------------------------------------------------------------------
+    # gitea_activate_profile
+    # -------------------------------------------------------------------------
+    def test_activate_profile_fails_when_disabled(self):
+        self._write_config(CONFIG_SWITCHING_DISABLED)
+        with patch.dict(os.environ, self._env("author-profile"), clear=True):
+            res = mcp_server.gitea_activate_profile(profile_name="reviewer-profile")
+        self.assertFalse(res["success"])
+        self.assertIn("switching is disabled", res["message"].lower())
+        self.assertIsNone(gitea_config._active_profile_override)
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header")
+    def test_activate_profile_succeeds_when_enabled(self, mock_auth, mock_api):
+        self._write_config(CONFIG_SWITCHING_ENABLED)
+        
+        # Setup mock responses for whoami checks
+        mock_auth.side_effect = ["token author-pass", "token reviewer-pass"]
+        mock_api.side_effect = [{"login": "author-user"}, {"login": "reviewer-user"}]
+
+        with patch.dict(os.environ, self._env("author-profile"), clear=True):
+            # Check before state
+            self.assertEqual(gitea_config.selected_profile_name(), "author-profile")
+            
+            res = mcp_server.gitea_activate_profile(profile_name="reviewer-profile")
+            
+            self.assertTrue(res["success"])
+            self.assertEqual(res["before_profile"], "author-profile")
+            self.assertEqual(res["before_identity"], "author-user")
+            self.assertEqual(res["after_profile"], "reviewer-profile")
+            self.assertEqual(res["after_identity"], "reviewer-user")
+            
+            # Global variable override should be set
+            self.assertEqual(gitea_config._active_profile_override, "reviewer-profile")
+            self.assertEqual(gitea_config.selected_profile_name(), "reviewer-profile")
+
+    # -------------------------------------------------------------------------
+    # gitea_check_pr_eligibility enhanced error clarity
+    # -------------------------------------------------------------------------
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value="token reviewer-pass")
+    def test_eligibility_failure_self_author(self, _auth, mock_api):
+        # PR is authored by "reviewer-user" and reviewer-user is trying to approve it.
+        mock_api.side_effect = [
+            {"login": "reviewer-user"}, # user whoami lookup
+            {"user": {"login": "reviewer-user"}, "state": "open", "head": {"sha": "abc123sha"}, "mergeable": True} # PR details
+        ]
+
+        with patch.dict(os.environ, self._env("reviewer-profile"), clear=True):
+            res = mcp_server.gitea_check_pr_eligibility(pr_number=42, action="approve")
+
+        self.assertFalse(res["eligible"])
+        self.assertEqual(res["active_identity"], "reviewer-user")
+        self.assertTrue(res["self_author"])
+        self.assertEqual(res["required_identity"], "Any Gitea user other than PR author 'reviewer-user'")
+        self.assertIn("Self-review/self-merge is forbidden", res["safe_next_step"])
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_eligibility_failure_missing_permissions(self, _auth, mock_api):
+        # PR is authored by "someone-else" and author-user (who lacks approve) is trying to approve it.
+        mock_api.side_effect = [
+            {"login": "author-user"}, # user whoami lookup
+            {"user": {"login": "someone-else"}, "state": "open", "head": {"sha": "abc123sha"}, "mergeable": True} # PR details
+        ]
+
+        self._write_config(CONFIG_SWITCHING_ENABLED) # Enable switching to verify fixable_by_profile_switch
+
+        with patch.dict(os.environ, self._env("author-profile"), clear=True):
+            res = mcp_server.gitea_check_pr_eligibility(pr_number=42, action="approve")
+
+        self.assertFalse(res["eligible"])
+        self.assertEqual(res["missing_permission"], "gitea.pr.approve")
+        self.assertTrue(res["fixable_by_profile_switch"])
+        self.assertFalse(res["requires_different_namespace"])
+        self.assertIn("Switch to a reviewer profile by calling gitea_activate_profile", res["safe_next_step"])
+
+    @patch("mcp_server.api_request")
+    @patch("mcp_server.get_auth_header", return_value="token author-pass")
+    def test_eligibility_failure_missing_permissions_switching_disabled(self, _auth, mock_api):
+        # PR is authored by "someone-else" and author-user (lacks approve) tries to approve it when switching is disabled.
+        mock_api.side_effect = [
+            {"login": "author-user"}, # user whoami lookup
+            {"user": {"login": "someone-else"}, "state": "open", "head": {"sha": "abc123sha"}, "mergeable": True} # PR details
+        ]
+
+        self._write_config(CONFIG_SWITCHING_DISABLED) # Disable switching
+
+        with patch.dict(os.environ, self._env("author-profile"), clear=True):
+            res = mcp_server.gitea_check_pr_eligibility(pr_number=42, action="approve")
+
+        self.assertFalse(res["eligible"])
+        self.assertEqual(res["missing_permission"], "gitea.pr.approve")
+        self.assertFalse(res["fixable_by_profile_switch"])
+        self.assertTrue(res["requires_different_namespace"])
+        self.assertIn("Switch to the reviewer MCP session", res["safe_next_step"])