majiayu000 Doctrine for authoring moo's own surfaces.
Frontmatter
A skill's frontmatter carries name and description; read any shipped SKILL.md for the current key set. The description is one line, and Claude Code caps it at 1024 characters.
Version lives in plugin.json only (DRY). The official Claude Code spec does not allow version in SKILL.md frontmatter.
Sizing
- Size a skill by a deletion pass, never a numeric cap — the same bar
hope/skills/card.mdsets for cards. - Put branch-specific content in files the skill opens when the branch is taken, and name them where they are needed.
- Decision tables > prose explanations.
Token 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 |
|---|---|
| A contract that must read identically in ≥2 skills | Fragment (<plugin>/skills/*.md, added to sync --files) |
| 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 | Hook |
| An unproven idea | hunch skill + HYPOTHESIS.md; graduates or dies |
Composition — artifacts and priming over imports:
- Skills compose through emitted artifacts (the card) and natural-language triggers, never cross-references.
- New pipeline stage when the cognitive mode changes (clarify WHAT ≠ decide HOW ≠ judge unsupervised work; find ≠ fix). One skill = one mode + one gate.
- Chain mechanics: each stage ends in a gate the user locks; the card carries only what the next stage can't re-derive; the shared contract is a fragment doc-gen'd into every stage.
- Two skills over one when triggers differ; a shared explanation the pair needs lives in CHANGELOG, not in either skill.
Hook Design
Hooks run beside the thread, never in front of it — they never gate.
Mode = two questions: does the foreground need the result, and now?
| Mode | When |
|---|---|
| Sync inject | Few lines of framing, computed instantly |
async — fire-and-forget |
Side effect only; surfaces as a file change, never re-engages the thread |
asyncRewake — fire-and-maybe-wake |
Off-thread check; exit 2 wakes Claude on a finding, exit 0 stays silent |
A hook that spawns headless claude -p copies its flag set from the two shipped hooks, where each flag is commented at the point of use (hope/hooks/judge.sh, hope/hooks/memory-write.sh), and keeps its verdict logic in one file shared with its eval harness.