---
"mattpocock-skills": minor
---

**Breaking:** rename **`writing-great-skills`** → **`writing-for-agents`**, restructure it, and add a new leading word.

The reference now covers any document an agent consumes — skills, `AGENTS.md` / `CLAUDE.md`, docs reached by a pointer — not just skills. `GLOSSARY.md` is merged into `SKILL.md` (one authoritative treatment per term; the `_Avoid_` synonym lists and the standalone Predictability definition are gone); the skill-only mechanics (frontmatter, model- vs user-invoked, router skills, the invocation cut of splitting) are disclosed to a new `SKILL-MECHANICS.md`. The skill is now **model-invoked**: it fires when creating or editing skills or modifying `AGENTS.md`/`CLAUDE.md`. `ask-matt`'s pointer updated. Reinstall under the new name; the old name is gone (no alias).

The pruning section gains **cache**. Single source of truth now reaches past the document into the environment — `package.json` scripts, config files, directory layout, `--help` output are themselves authoritative, so a doc that restates them is a cache of a lookup, earning its load only when the lookup is expensive. The positive target: cache what the agent cannot find by looking (unwritten conventions, the reason behind a choice, gotchas no config confesses), and leave one-file, one-command lookups to the environment, where they cannot go stale.