Scan Codebase Health

---
name: scan-codebase-health
version: 2.0.0
description: '[Documentation] Use when detecting codebase health issues — unused exports, doc count-drift, orphan files, stale config references.'
---

## Quick Summary

**Goal:** Detect structural rot in AI-assisted codebases — dead code, count-drift, orphan files, stale configs, dead feature flags, broken cross-references. Works on any project via `docs/project-config.json`.

**Workflow:**

1. **Classify** — Load config, detect available tooling (graph.db, CI, feature-flag patterns)
2. **Run Detections** — Execute 7 detection categories (graph-dependent checks skipped if no graph.db)
3. **Fresh-Eyes Review** — Verify findings before writing report
4. **Generate Report** — Write to `plans/reports/codebase-health-scan-{YYMMDD}.md`
5. **Present Summary** — Show actionable findings with severity levels

**Key Rules:**

- Generic — reads all paths from project-config.json, never hardcodes project names
- Graceful degradation — graph-dependent checks skipped if `.code-graph/graph.db` not found
- Report format — each finding has `file:line`, category, severity (HIGH/MEDIUM/LOW), suggested action
  **MUST ATTENTION** NEVER report a finding without `file:line` proof

---

# Scan Codebase Health

## Phase 0: Classify & Detect

**Before any other step**, in parallel:

1. Read `docs/project-config.json` for the `codebaseHealth` section:

```json
{
    "codebaseHealth": {
        "sourcePaths": ["{discovered-source-root}/"],
        "docPaths": ["docs/"],
        "configPatterns": ["**/appsettings*.json", "**/environment*.ts"],
        "excludePaths": ["node_modules", "dist", "bin", "obj"]
    }
}
```

If `codebaseHealth` section is missing, discover source roots from project config, manifests, and populated code directories; use `docPaths: ["docs/"]` when docs exist.

2. Detect available tooling to determine which phases to run:

| Signal                                                                          | Phase Enabled                                     |
| ------------------------------------------------------------------------------- | ------------------------------------------------- |
| `.code-graph/graph.db` exists                                                   | Phase 3 (Unused Exports) + Phase 4 (Orphan Files) |
| CI config found (`.github/workflows`, `azure-pipelines.yml`)                    | Phase 6 (CI Health) — optional                    |
| Feature flag patterns found (`FeatureFlags`, `IFeatureManager`, `LaunchDarkly`) | Phase 6 (Dead Feature Flags)                      |
| Cross-reference patterns in docs (`file:line`, `[link]()`)                      | Phase 7 (Broken Cross-References)                 |

3. Create `TaskCreate` entries for each enabled phase before proceeding.

**Evidence gate:** If `docs/project-config.json` not found and no detectable source paths, report and ask user for guidance. DO NOT guess project structure.

## Phase 1: Doc Count-Drift Detection (No Graph Required)

**Think:** Which numeric claims in docs can actually be verified? What's the drift threshold that signals a real maintenance problem vs normal growth?

Scan `docs/` **and the AI-harness instruction surface when present** (`.claude/**/*.md`, root `AGENTS.md`, `CLAUDE.md`) for numeric claims: "N files", "N tests", "N hooks", "N services", "N skills", "N components", "N stages", "N verifiers", "N agents", "N workflows". The harness docs embed counts that are directly derivable by globbing `.claude/` (skill dirs, hook entries, `scripts/**/verify-*` scripts, pipeline stages, agent files, `workflows.json` entries) — the highest-drift claims because a new skill/verifier/stage bumps the real count while the prose claim stays frozen. This scope is generic: any project carrying a `.claude/` harness gets it; it hardcodes no project- or framework-specific count.
For each claim:

1. Extract number and what it counts
2. Glob/grep to verify actual count
3. Flag if actual differs from claimed

**Severity thresholds:**

- Drift ≤10% → LOW (normal growth)
- Drift >10% and ≤30% → MEDIUM (needs update)
- Drift >30% → HIGH (significantly stale)
- Claim cannot be verified → MEDIUM (ambiguous claim)

Write findings incrementally to report after each doc scanned. NEVER batch at end.

## Phase 2: Stale Config Reference Detection (No Graph Required)

**Think:** Which config values reference code artifacts (class names, module names, connection strings)? Could those artifacts have been renamed or deleted?

For each file matching `configPatterns`:

1. Extract class names, module names, or connection strings referenced
2. Grep codebase to verify each reference still exists
3. Flag missing references as HIGH severity

**Evidence gate:** NEVER flag a reference as stale without attempting grep. Confidence <80% → flag as MEDIUM "unverified" only.

## Phase 3: Unused Exports Detection (Graph Required)

**Skip if `.code-graph/graph.db` does not exist — log "Phase 3 skipped: no graph.db".**

**Think:** Which public API surface has zero consumers? Could be dead code, or could be an intentional entry point — distinguish by file type.

For key exported symbols in source files:

1. Run `python .claude/scripts/code_graph query importers_of <symbol> --json`
2. Flag symbols with zero importers as MEDIUM severity
3. Exclude known entry points (main files, test files, config files, startup files)

## Phase 4: Orphan File Detection (Graph Required)

**Skip if `.code-graph/graph.db` does not exist — log "Phase 4 skipped: no graph.db".**

Find source files (.ts,.cs,.py, etc.) with zero inbound edges:

1. Run `python .claude/scripts/code_graph query importers_of <file> --json`
2. Flag files with zero importers as LOW severity (may be entry points)
3. Exclude known entry points

## Phase 5: Pattern Drift Detection (No Graph Required)

**Think:** Where does the same pattern appear across services/modules? Does it look different in different places? Is that divergence intentional or accidental?

Compare the same pattern across services/modules:

1. Pick a pattern (e.g., repository registration, service configuration, error handling)
2. Grep across all services/modules
3. Flag inconsistencies as MEDIUM severity

## Phase 6: Dead Feature Flag Detection (If Feature Flags Detected)

**Skip if no feature flag patterns found in Phase 0.**

**Think:** Which flags exist in config but have no code references? Which code references flags that no longer exist in config?

1. Grep for feature flag names in config files
2. Grep for feature flag usage in code
3. Flag config-only flags (no code usage) as LOW
4. Flag code-only flags (no config entry) as HIGH (runtime error risk)

## Phase 7: Broken Cross-Reference Detection (No Graph Required)

**Think:** Which doc links point to files that no longer exist? Which `file:line` references in docs are stale?

For docs containing markdown links `[text](path)` or `file:line` references:

1. Extract all file path references
2. Glob to verify each path exists
3. Flag missing paths as MEDIUM severity

## Phase 8: Fresh-Eyes Review

**Before writing final report**, spawn a fresh sub-agent (zero memory) to:

- Sample 5-10 findings from the report
- Verify each has a real `file:line` evidence source
- Check: is the severity classification justified by the description?
- Flag false positives (things flagged but actually acceptable)

Max 2 rounds → escalate to user if review finds >30% false positive rate.

## Phase 9: Generate Report

Write to `plans/reports/codebase-health-scan-{YYMMDD}.md`:

```markdown
# Codebase Health Scan Report

**Date:** {YYYY-MM-DD}
**Phases Completed:** {N}/{total} ({reason for skipped phases})
**Findings:** {total} ({HIGH} high, {MEDIUM} medium, {LOW} low)

## Summary

| Phase                   | Status                              | Findings   |
| ----------------------- | ----------------------------------- | ---------- |
| Doc Count-Drift         | Scanned                             | N findings |
| Stale Config Refs       | Scanned                             | N findings |
| Unused Exports          | Scanned/Skipped (no graph.db)       | N findings |
| Orphan Files            | Scanned/Skipped (no graph.db)       | N findings |
| Pattern Drift           | Scanned                             | N findings |
| Dead Feature Flags      | Scanned/Skipped (no flags detected) | N findings |
| Broken Cross-References | Scanned                             | N findings |

## Findings

### HIGH Severity

- `{file}:{line}`: {description} — Action: {action}

### MEDIUM Severity

- `{file}:{line}`: {description} — Action: {action}

### LOW Severity

- `{file}:{line}`: {description} — Action: {action}

## False Positives (Fresh-Eyes Review)

{Findings dismissed by Round 2 review with reasoning}
```

---

> **[IMPORTANT]** Use `TaskCreate` to break ALL work into small tasks BEFORE starting.

<!-- SYNC:critical-thinking-mindset -->

> **Critical Thinking Mindset** — Apply critical thinking, sequential thinking. Every claim needs traced proof, confidence >80% to act.
> **Anti-hallucination:** Never present guess as fact — cite sources for every claim, admit uncertainty freely, self-check output for errors, cross-reference independently, stay skeptical of own confidence — certainty without evidence root of all hallucination.

<!-- /SYNC:critical-thinking-mindset -->

<!-- SYNC:output-quality-principles -->

> **Output Quality** — Token efficiency without sacrificing quality.
>
> 1. No inventories/counts — AI can `grep | wc -l`. Counts go stale instantly
> 2. No directory trees — AI can `glob`/`ls`. Use 1-line path conventions
> 3. No TOCs — AI reads linearly. TOC wastes tokens
> 4. No examples that repeat what rules say — one example only if non-obvious
> 5. Lead with answer, not reasoning. Skip filler words and preamble
> 6. Sacrifice grammar for concision in reports
> 7. Unresolved questions at end, if any

<!-- /SYNC:output-quality-principles -->

<!-- SYNC:ai-mistake-prevention -->

> **AI Mistake Prevention** — Failure modes to avoid on every task:
>
> **Re-read files after context changes.** Context compaction, resume, or long-running work can make memory stale; verify current files before acting.
> **Verify generated content against source evidence.** AI hallucinates APIs, names, claims, and document facts. Check the relevant source before documenting or referencing.
> **Check downstream references before deleting or renaming.** Removing an artifact can stale docs, generated mirrors, configs, and callers; map references first.
> **Trace the full impact chain after edits.** Changing a definition can miss derived outputs and consumers. Follow the affected chain before declaring done.
> **Verify ALL affected outputs, not just the first.** One green check is not all green checks; validate every output surface the change can affect.
> **Assume existing values are intentional — ask WHY before changing OR flagging one as a defect.** Before changing or reporting a constant, limit, flag, cutoff, wording, or pattern, read nearby context and history, the CALLER's ordering, and 2+ sibling call sites of the same convention. A doc stating WHAT without WHY is missing rationale, not proof of a missing guard.
> **Surface ambiguity before acting — don't pick silently.** Multiple valid interpretations require an explicit question or stated assumption with risk.
> **Assert the outcome your system owns, not the intermediate state your infrastructure owns.** When verifying async work, assert the final business state — never the delivery/retry bookkeeping held in shared infrastructure that any co-running process can write. Such a check passes when run alone and flakes the moment anything else shares that infrastructure.
> **Keep shared guidance role-relevant.** Universal guidance must help every receiving skill or agent; code-specific obligations belong only in code-specific protocols.

<!-- /SYNC:ai-mistake-prevention -->

<!-- SYNC:output-quality-principles:reminder -->

**IMPORTANT MUST ATTENTION** output quality: no counts/trees/TOCs, 1 example per pattern, lead with answer.

<!-- /SYNC:output-quality-principles:reminder -->

<!-- SYNC:critical-thinking-mindset:reminder -->

**MUST ATTENTION** apply critical + sequential thinking — every claim needs appropriate traced evidence (`file:line` for repo/code claims; source URL or artifact section for research, product, content, and docs claims); confidence >80% to act, <60% DO NOT recommend. Anti-hallucination: never present guess as fact, admit uncertainty freely, cross-reference independently, stay skeptical of own confidence.

<!-- /SYNC:critical-thinking-mindset:reminder -->

<!-- SYNC:ai-mistake-prevention:reminder -->

**MUST ATTENTION** apply AI mistake prevention — verify generated content against evidence, trace downstream references before deleting or renaming, verify all affected outputs, re-read files after context loss, and surface ambiguity before acting.

<!-- /SYNC:ai-mistake-prevention:reminder -->

<!-- SYNC:parallel-subagent-dispatch -->

> **Parallel Sub-Agent Dispatch** — Plan parallelism the moment a task breakdown exists, BEFORE executing it — running provably independent tasks sequentially wastes wall-clock. Applies to every multi-step job: workflow steps, planning, batch updates, investigation, research, scans, reviews, doc sync. **Plan execution is metadata-gated, NEVER default-parallel** — fan-out follows ONLY what the plan declares (`PAR`/`SEQ` tags + per-phase write set); an untagged plan runs sequentially — why: a derived write set cannot see cascade or generated writes.
>
> 1. **Tag every task `PAR` or `SEQ`.** `PAR` = inputs exclude every pending task's output AND write set disjoint from every other `PAR`. Else `SEQ` — MUST ATTENTION name the dependency forcing it.
> 2. **Group `PAR` into waves.** No edge between members. Two writers of one file NEVER share a wave. Read-only work (search, investigation, review, research) parallelizes freely.
> 3. **Declare before dispatch:** `Parallel plan: wave 1 = [...] · wave 2 = [...] · SEQ = [...] (reason)`.
> 4. **Spawn each wave in ONE message** — every `Agent` call in one response, NEVER dripped per turn. Route each task to its specialist (`.claude/skills/shared/sub-agent-selection-guide.md`); NEVER `code-reviewer` as catch-all.
> 5. **Brief each sub-agent self-contained:** goal · scope + owned files · reference docs · return contract (summary + `Full report:` path, per SYNC:subagent-return-contract) · incremental persistence to `plans/reports/` (per SYNC:incremental-persistence).
> 6. **Barrier per wave.** Advance ONLY after EVERY member returns (a skipped conditional counts as returned). Merge, mark each task completed/skipped, THEN dispatch the next wave. Mutating steps wait for the barrier.
> 7. **One level deep.** A dispatched sub-agent executes its own brief; further fan-out stays the orchestrator's job unless that agent's `.claude/agents/*.md` definition authorizes it.
>
> **NEVER parallelize:** tasks sharing a write target · a task consuming a pending task's output · trivial single-file work (dispatch overhead > gain) · an order a skill or workflow explicitly fixes · gates awaiting user approval.
>
> **Blocked until:** MUST ATTENTION every task tagged PAR/SEQ with a named reason per SEQ · waves declared + write-set disjointness checked · each wave spawned in ONE message · barrier honored before the next wave.

<!-- /SYNC:parallel-subagent-dispatch -->

<!-- SYNC:parallel-subagent-dispatch:reminder -->

- **MANDATORY** After planning tasks, tag each PAR/SEQ and spawn every PAR wave as parallel sub-agents in ONE message — default parallel for workflows, batch updates, investigation, research, reviews; plan execution fans out ONLY on what the plan declares.
- **MANDATORY** Disjoint write sets per wave · all-return barrier before the next wave · specialist routing · sub-agents NEVER fan out further unless their own agent definition authorizes it.

<!-- /SYNC:parallel-subagent-dispatch:reminder -->

<!-- SYNC:project-protocol-overlay -->

> **Project Protocol Overlay** — Before executing this skill, resolve any PROJECT overlay rules layered onto it: match this skill's name against the `Target` column of the project's skill-protocol index (`docs/project-reference/skill-protocols-reference.md` by default; a `referenceDocs` entry in `docs/project-config.json` overrides the path), taking the most specific matching tier ONLY — exact name > glob > `*`. **That precedence orders overlays against EACH OTHER, never against this skill.** Read ONLY the matched bodies, resolved as `<protocols-dir>/<Name>.md`; a row's Body link is display text, never a read path. A matched body that is missing or malformed is REPORTED and skipped — never reconstructed from the index Description. No index, or no match -> proceed with no overlay, silently. Full contract: `.claude/skills/project-skill-protocol/references/registry.md`.
>
> Overlays are **ADDITIVE ONLY**: they ADD rules on top of this skill's own protocol and NEVER replace, override, disable, or reinterpret a rule it already states — removing every overlay must return this skill to exactly its documented behavior. An overlay is a BRIEF, not an authority escalation: it can NEVER waive a workflow gate, git discipline, a review gate, or a user-confirmation gate. A genuine overlay-vs-skill conflict, or two equally-specific overlays that directly contradict -> surface both to the user; NEVER resolve silently.

<!-- /SYNC:project-protocol-overlay -->

<!-- SYNC:project-protocol-overlay:reminder -->

**MUST ATTENTION** resolve project protocol overlays for this skill BEFORE executing — most specific matching tier only (exact > glob > `*`, which ranks overlays against each other, NEVER against this skill), read only matched bodies at `<protocols-dir>/<Name>.md`; a missing or malformed body is reported, never reconstructed. Overlays are ADDITIVE ONLY (they never replace this skill's own rules) and are a brief, NEVER an authority escalation; an equal-specificity contradiction goes to the user.

<!-- /SYNC:project-protocol-overlay:reminder -->

## Closing Reminders

**IMPORTANT MUST ATTENTION** break work into small `TaskCreate` tasks BEFORE starting — one per phase

**MUST ATTENTION — Protocols in force (concise digest of the SYNC/shared blocks this skill carries):**

- **Critical Thinking:** apply critical+sequential thinking; traced `file:line` proof, >80% to act.
- **Output Quality:** no counts/trees/TOCs; 1 example per pattern; lead with answer.
- **AI Mistake Prevention:** verify generated content against evidence, trace downstream references, verify all affected outputs, re-read after context loss, surface ambiguity.
- **Parallel Sub-Agent Dispatch:** Tag tasks PAR/SEQ, group PAR into disjoint-write-set waves, spawn each wave in ONE message, barrier before advancing.

**IMPORTANT MUST ATTENTION** detect available tooling in Phase 0 — never assume graph.db exists
**IMPORTANT MUST ATTENTION** NEVER report a finding without `file:line` evidence
**IMPORTANT MUST ATTENTION** write findings incrementally after each phase — NEVER batch at end
**IMPORTANT MUST ATTENTION** severity thresholds are concrete: HIGH = runtime failure risk; MEDIUM = drift/dead code; LOW = cleanup candidate
**IMPORTANT MUST ATTENTION** Phase 8 fresh-eyes review is mandatory — prevents false positives from rationalization

**Anti-Rationalization:**

| Evasion                                      | Rebuttal                                                                              |
| -------------------------------------------- | ------------------------------------------------------------------------------------- |
| "Graph not needed, skip Phases 3-4"          | Phases 3-4 are explicitly gated — state skip reason in report, don't silently omit    |
| "Count drift is small, LOW severity is fine" | Apply the threshold table: >10% = MEDIUM, >30% = HIGH. No discretionary override.     |
| "Finding looks valid, skip Round 2 review"   | Main agent rationalizes own findings. Fresh-eyes is non-negotiable.                   |
| "No feature flags found, skip Phase 6"       | Log "Phase 6 skipped: no feature flag patterns detected" in report                    |
| "Config reference might still exist"         | Grep to verify. Confidence <80% → flag as MEDIUM "unverified" not LOW "probably fine" |

**[TASK-PLANNING]** Before acting, analyze task scope and break into small todo tasks and sub-tasks using TaskCreate.