--- name: moo-authoring description: Use when adding or changing a skill, hook, or runtime file in this repo — including deciding which unit a new capability should be. metadata: internal: true --- Doctrine for authoring moo's own surfaces. ## Frontmatter No `when_to_use`. A condition that follows what the skill does is marked `Use when .` A description may also open with the condition and stop there, where naming the capability would discriminate nothing. A skill that stays in this repo declares `metadata.internal: true`. Version lives in `plugin.json` only. Claude Code spec does not allow `version` in SKILL.md frontmatter. ## Sizing - Size a skill by a deletion pass using a /reduce loop, never a numeric cap. - Decision tables > prose explanations. ## Efficiency - Challenge every sentence: "Does Claude need this?" - Bullets for enumerable items; a paragraph when the point is one connected argument. - No vague terminology; pick one term per concept. ## Skill Design Phrase design decisions as "X over Y: reason". **Unit choice** — behavior inlines at build, data references at runtime; a skill's firing is probabilistic, so behavior that must run every time is a hook: | The new thing is... | Unit | | ---------------------------------------------------- | -------------------------------------------------- | | Data selected per use (catalog, profile, corpus) | Runtime file | | A trigger + procedure that stands alone | Skill | | A trigger only the human perceives | Skill with `disable-model-invocation: true` | | Behavior that must run every time, deterministically | Function hook aka claude code mods | | An unproven idea | hunch skill + `HYPOTHESIS.md`; graduates or dies | | Doctrine for this repo's own surfaces | Repo-local skill in `.claude/skills/`; never ships | Before building any unit, count how often its target situation occurs in real session transcripts, and weigh each case by what the miss cost. A rare, cheap situation caps the value whatever the build's accuracy; a planted test prompt proves the mechanism, never the value. **Composition — name-calls, never imports:** - Skills compose by name: a composer names a move and invokes it with the Skill tool; a body never inlines another body. - New skill when the cognitive mode changes (clarify WHAT ≠ decide HOW ≠ judge unsupervised work; find ≠ fix). One skill = one mode + one gate. - Two skills over one when triggers differ; a shared explanation the pair needs lives in this file, which owns skill-design reasoning, not in either skill. - A body names a sibling in exactly two places: a refusal, and a route — wherever in the body those sit. There the name _is_ the refusal's or the route's content, and a reader without it is stranded. - Ending over hand-off: a finished run states what is now settled and what is still open, in its own words. Naming who handles it next hardcodes the graph n², so one trigger change edits every sibling. **Turning to the user — information decides who is asked, never the skill's habit.** A skill states once, over every point where it asks or hands something over, `only what nothing in reach settles; read what does, and say where its answer came from`, in those words. In reach: the repo, its docs and history, the record, the user's notes and accounts, and any read-only tool the session has, read at the source that settles the fact. A step that is free, reversible and inside the work is done and its result reported, never handed over as a link, path or command. What stays the user's: | Turn to the user for | Unless | The turn carries | | ------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- | ------------------------------------------------------------- | | What only they hold — what they want, their reasons, taste and limits, what they understand | A wrong guess costs less to undo than the question costs: state it, they correct it | What was read, so they answer only what is left | | An act only their login or authority can take | — | The work done: values filled, request drafted, one exact step | | An act that spends their money or time, reaches outside the work, or can't be undone | Their words, this session or recorded in reach, authorize that act and its content | The act ready to run on their yes | A fact out of reach is named as a gap wherever a claim or choice rests on it. **Output form — bound by what the skill hands back, never by one shared sentence.** Plain words is the only part that holds across all three: | The Output hands back | Bound it by | | -------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- | | Something the agent restated in its own words | As short as it goes with nothing _the skill can't afford to drop_ lost — name that thing, it differs per skill | | The user's own words — a record, an amended proposal | Preserving them. A compression clause here destroys the result | | A structure the reader navigates — verdict then evidence, a case set then a rule | Bounding each part where a reader would pad it, never the whole | A cap counted in lines is a compression budget on a handed-back artifact — replace it. A cap on one turn of a loop is pacing, and the rest arrives on the user's next pull — keep it. ## Hook Design Every hook is a function hook: it reaches the human with no model turn. The API is early access; `plugin-authoring` and `/plugin-types` are the reference for every event and call. - A hook never starts a turn the human didn't ask for: no wake, no `$.prompt.submit` of its own. - What a hook finds waits where the human looks next, the band above the prompt, and appears there only while it holds something. Detail unfolds on a press and folds back. - A hook hands to Claude only on the human's Enter: `$.prompt.fill` a sentence start they finish, with any bulk added as `prompt.submit` context. - Work longer than one dispatch runs unawaited, so the turn's end is never held. - State lives in `$.state` (this session) or `$.store` (across sessions), never in temp files. Module variables hold only what a hot reload may drop: it drops them. - A failure shows once, as a toast, and the event passes on. - A pane or band is verified on events copied from real session transcripts, one per shape it renders; a synthetic event alone never verifies it. - One hooks module per plugin; a second part composes into it. A second registration on the same event and matcher in one plugin is dropped silently. A hook that spawns headless `claude -p` copies its flag set from `hope/hooks/judge.sh`, where each flag is commented at the point of use.