> 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.