Dependency / import graph analysis. Answer "what does this file import", "what imports this module", "what's the project's import topology", "show me the sitemap" without reading every file's import block. Use when: - "What does file X depend on" / "what imports module Y" - "Is module Z a leaf or a hub in the import graph" - "Show me the project sitemap" (which files glue what together) - "Are there circular imports" - Planning a module extraction: who'd you break Replaces: grep-for-import-statements + manual graph walking (~5k tokens for non-trivial repos) with 1 MCP call (~500 tokens).

> **Source of authority.** From `docs/agent-tooling-gap-report.md` line 58: > > > Every feature update must run the self-hosted workflow: `edit action=safe` > > before risky edits, `health action=file` on changed files, `edit action=impact` > > after edits, its reported `verification_command`, then

Fast file + content search with code-aware sizing. Replaces Read/Grep/find for routine "where is this file" / "grep for X" / "show me lines 10-20 of Y" questions. Returns file paths + line numbers + a sized chunk, not the whole file. Use when: - "Find files matching <pattern>" / "show me all *.yml under config/" - "Grep for 'TODO' / 'FIXME' / 'TODO\\(perf\\)' / regex anywhere" - "How big is <file>" / "is this file too large to read fully" - "Show me lines 50-80 of <file>" / "read just the relevant slice" - "Find all files matching name + containing string" Replaces: native find + grep + cat invocations (~3-10k tokens for big repos) with single MCP calls (200-500 tokens).

> 47 MCP tools live in this repo; this skill exposes the 6 that answer > "who is connected to what" — the questions agents waste the most tokens on > when they fall back to grep.

Project & file health grading + dead-code detection + watch-daemon for grade drops. Answer "how healthy is this codebase", "what's rotting", "which files need attention", "alert me when something degrades" in one workflow. Use when: - Triaging a codebase: "what should we clean up first?" - Pre-PR check: "did this change make health worse?" - User asks "any dead code?" / "any rotting hot spots?" - Starting long-running session, want auto-alerts on degradation - Project-wide quality reporting Replaces: 5-10 grep/read calls + manual heuristics + spreadsheet (~20k tokens) with 2-3 MCP calls (~2k tokens).

Manage the persistent AST cache / index. Refresh, force-rebuild, inspect cache state, diff one file's AST between commits, advise on parser readiness for a language. Mostly ops/infra, not daily agent work. Use when: - "Re-index the project" / "force rebuild AST cache" - "Why is callees returning unknown" (likely stale index) - "AST diff this file vs last commit" (structural diff, not text diff) - "What language plugins are ready / which are stubs" - Setting up the project for the first time (autoindex) Replaces: manual `rm -rf .ast-cache && reindex` + reading plugin docs.

> Three signals, one ranked list. Health × churn × dead-code → the five files > you'd refactor first if you had a week. Each row carries a target symbol, a > blast radius, and a concrete action.

> Per-symbol modification frequency persisted in `ast_symbol_activation`. > Computed from `git log --follow -p -U0` hunk attribution at index time. > Symbols with `mod_count_30d >= 5` auto-trigger CAUTION in change_impact.