# Skill Craft

> Use to create, revise, or audit Agent Skills: SKILL.md, triggers, progressive disclosure, fixtures, overlap, token cost. Defaults to read-only audit; edits need authority. Not for plugin packaging (use plugin-creator) or delivery (use implement).

- Skill: `mblauberg/skill-craft` (Agent Skill, multi-file: 7 files)
- Install (CLI): `npx skillmds@latest add mblauberg/skill-craft`
- Raw SKILL.md: https://api.skillmd.com/api/skills/mblauberg/skill-craft/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: mblauberg (https://skillmd.com/u/mblauberg)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/mblauberg/skill-craft

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# Skill craft

A skill is a reusable, triggerable procedure, not a solved-task narrative
and not a place to park static reference. Every skill earns its slot on four
pillars: **Trigger** (fires on the right requests, stays silent on adjacent
ones), **Structure** (frontmatter contract, progressive disclosure, soft
length budgets), **Steering** (leading words and bright-line rules over
repeated emphasis), and **Pruning** (cutting sediment, duplication, sprawl
and no-ops before they ship).

This skill has two branches and defaults to the safer one.

- New or materially revised skill → [references/author.md](references/author.md).
- Assessment of an existing skill, read-only → [references/audit.md](references/audit.md).
- **Default with no explicit authoring request: audit.** Do not cross
  audit → edit without an authority envelope naming `implement` as
  action-owner; surface that requirement instead of silently fixing what an
  audit finds.

## Shared doctrine

Both branches follow this without restating it in two voices:

- **Three-mode invocation:** direct audit; direct authoring under authority;
  or composed, where audit is a companion to a primary lifecycle owner (for
  example `implement`) that stays the action-owner.
- **Budgets:** soft ~500-word body per branch file; the standing
  catalogue-description lever is governed in `MAINTAINING.md`; link it,
  don't restate the number here.
- **Token model, three-tier:** always-loaded frontmatter, triggered branch
  body, and entrypoint references loaded at one hop. Reference documents may
  link to sibling references, but that depth is not recursively enforced by
  `check_harness.py`.
- **Reuse boundary:** global skills express cross-project triggers, procedures
  and gates. Convert contextual values into parameters, keep examples
  synthetic and leave project policy local. Global promotion requires a
  reusable trigger, artifact, fixture and ownership boundary. When evidence is
  limited, keep it opt-in and provisional. Follow the repository gate in
  [MAINTAINING.md](../../MAINTAINING.md).
- **Trigger fixtures:** positive, negative, boundary and composition cases.
  A keyword match is a candidate, not ground truth. Changes to routing text
  re-run the held-out set.
- **Contract-test boundary:** a contract test protects a machine-enforced
  invariant, never the prose that describes it. If the invariant has no
  enforcing script, the correct output is either an enforcing script or
  nothing, not an assertion about wording.
- **Failure taxonomy:** name the failure, don't just gesture at quality:
  premature-completion, duplication, sediment, sprawl, no-op, negation-only.
- **Description contract:** front-load the first 250 characters with trigger
  words and the nearest exclusion; keep boundary-routing negation explicit
  (name the skill to use instead); never drop it for brevity.
- **Provenance:** any adaptation from a third-party source records source
  URL, version/commit, retrieval date and licence in the repository
  `THIRD_PARTY_NOTICES.md` index, with the full licence text under `LICENSES/`.
  See [THIRD_PARTY_NOTICES.md](../../THIRD_PARTY_NOTICES.md) for this skill's
  own Skill Optimizer lineage.