writing-skillslisted

A skill exists to wrangle determinism out of a stochastic system. **Predictability** — the agent taking the same _process_ every run, not producing the same output — is the root virtue; every lever below serves it. **Bold terms** are defined in [`GLOSSARY.md`](GLOSSARY.md); look them up there for the full meaning. **What to write or review:** $ARGUMENTS — a skill path, a draft, or a request; with no argument, the skill under discussion. Apply every rule below to it. The work is done when each one has been held against that target and either cleared or named as a defect — not when the rubric has been read. ## Invocation Two choices, trading different costs: - A **model-invoked** skill keeps a **description**, so the agent can fire it autonomously _and_ other skills can reach it (you can still type its name too). It contributes to **context load** — the description sits in the window every turn. Mechanics: omit `disable-model-invocation`, and write a model-facing description with rich trigger phrasing ("Use when the user wants…, mentions…"). - A **user-invoked** skill strips the description from the agent's reach: only you, typing its name, can invoke it — and no other skill can. Zero context load, but it spends **cognitive load**: _you_ are the index that must remember it exists. Mechanics: set `disable-model-invocation: true`; the `description` becomes human-facing — a one-line summary, trigger lists stripped. Pick model-invocation only when the agent must reach the ski