# Ablate > Use for /ablate and $ablate. Finds which parts of a SKILL.md earn their tokens and rebuilds the skill without the rest. Use when asked to ablate, audit, shrink, slim, or trim a skill, when skill bloat or per-session context cost comes up, or to work out which sections of a skill are load-bearing. - Skill: `mbanderas/ablate` (Agent Skill, multi-file: 23 files) - Install (CLI): `npx skillmds@latest add mbanderas/ablate` - Raw SKILL.md: https://api.skillmd.com/api/skills/mbanderas/ablate/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Security - Author: mbanderas (https://skillmd.com/u/mbanderas) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/mbanderas/ablate --- # Maestro: Ablate Two phases. **Phase A** is a static audit: one reasoning pass per skill, no trial runs, covers everything. **Phase B** is an empirical loop: baseline, stub, measured add-back, real `claude -p` runs, expensive. **Run Phase A first, always.** Scripts do the mechanics, take `--help`, and are invoked by absolute path from this skill's directory. The judgement is yours: classification, task authoring, mapping failures to sections. ## Before anything writes `~/.claude/skills/` has no version control by default, and `apply.mjs` destructively rewrites `SKILL.md` files — it refuses to touch a skill whose own files are uncommitted. Git is the rollback path; the `.bak` is a convenience, not a safety net. ```sh cd ~/.claude/skills && git init && git add -A && git commit -m "chore: snapshot skills" ``` ## Cost — say this before starting Phase B Phase A costs one reasoning pass per skill. Phase B **spends real money against the user's own subscription, consumes their rate limits, and competes with the session they are in** — budget 30–60 nested runs per skill plus grading. Never begin one without saying so and getting a yes. ## Start with the inventory `node scripts/inventory.mjs --top 20` ranks targets by lines × recorded usage. - **Zero-usage skills are a roster-prune candidate, not an ablation target.** A description loads into every session whether the skill is invoked or not, so archiving an unused one helps every session; shrinking a skill nobody calls saves nothing. - **Vendor-maintained skills get re-pinned upstream, not ablated.** Ablating forks them. ## Phase A — static audit ```sh node scripts/sections.mjs node scripts/apply.mjs --decisions d.json --dry-run node scripts/apply.mjs --decisions d.json node scripts/report.mjs ``` Read `references/static-rubric.md` before deciding and `references/classify.md` for the gotcha inventory. Four rules, none negotiable: - **Extract before drop.** A template or lookup table is misplaced, not dead: in prose it costs tokens every invocation, in a referenced file it costs nothing until read. - **Phase A never drops a gotcha.** A gotcha may only be cut if a task built to trigger the failure it guards passes without it, which a static pass cannot establish. - **`kind`, prose ratio and section size order the search. They never justify a drop.** The best content in most skills, verification steps and irreducible gotchas, is pure prose. - **Every drop names a rubric category.** If you cannot name one, keep it. Hand over the diff, the decision table with low-confidence drops on top, and the gotcha inventory. ## Phase B — empirical loop Follow `references/protocol.md`. The commands, in order: ```sh node scripts/labinit.mjs --model node scripts/run.mjs --variant control --task --reps 2 node scripts/stub.mjs node scripts/run.mjs --variant stub --task --reps 2 node scripts/run.mjs --gate # BLOCKING node scripts/stub.mjs --keep --label node scripts/run.mjs --variant iter --iter --task --reps 2 node scripts/run.mjs --grade --a --b ``` - **`run.mjs` is the only way to start a trial or a grading call.** Improvised setup drifts, and drift invalidates every comparison in the lab. - **`--gate` is blocking; exit 2 means halt.** A stub that passes everything means the harness is broken, not that the skill body is worthless. - **A split result across reps is a keep.** Two reps disagreeing means you do not know. - Delete the lab when done: `/config/` holds a copy of the user's credentials. Validate the rig first per `fixtures/README.md`. Do not self-ablate this skill. ## The two gates Grading in between is autonomous. **Gate 1, before the runs:** operator reviews `bar.md`, `tasks.json`, the gotcha inventory — a bad bar wastes every run after it. **Gate 2, after the rebuild:** rebuilt versus control per task, dropped and extracted with iteration evidence, thin-margin drops flagged for individual veto. Then spot-check the rebuild in real work: the clean room cannot see the context pressure that motivates the method. ## References `references/`: `static-rubric.md` Phase A · `classify.md` deterministic-vs-taste and gotchas · `protocol.md` the loop · `bar-template.md` success criteria. Also `SPIKE.md` (why isolation works) and `fixtures/README.md` (rig validation).