/craft-skill

# story: e45s02
# story: e45s12
# story: e79s02
name: craft-skill
model: sonnet
effort: standard
description: Create new bigpowers skills with proper structure, progressive disclosure, and bundled resources. Use when user wants to create, write, or build a new skill for the bigpowers lifecycle.

Craft Skill

> **HARD GATE** — Do NOT name a skill without a two-word verb-noun pair. Do NOT merge a new skill without running `sync-skills.sh`. Generated `.cursor/rules/` and `.gemini/` artifacts MUST match the source SKILL.md.

CSO Description Discipline (e45s02)

The YAML `description` is the **Catalog Selection Object** — the only field agents see when picking a skill.

| Rule | Limit | |------|-------| | Max length | 1024 characters | | Voice | Third person | | Content | Capability + `Use when …` triggers only | | Forbidden | Workflow steps, phase chains, numbered lists, `→ verify:`, HARD GATE prose |

Move process detail into the SKILL.md body or REFERENCE.md — never into `description`.

Agentic STE body discipline (e79s02)

Skill-body instructional prose MUST follow [AGENTIC-STE.md](../../docs/AGENTIC-STE.md).

| Rule | Limit | |------|-------| | Sentence length | ≤20 words per instruction sentence | | Voice | Imperative, active | | Directive terms | MUST, MUST NOT, NEVER, ALWAYS, DO, DO NOT | | Banned modals | should, might, could, may, consider, try, generally, typically | | Scope | SKILL.md body only — not YAML `description`, not `terse-mode` output |

> **HARD GATE** — Do NOT merge a new or edited skill until `bash scripts/validate-agentic-ste.sh --strict skills/<name>/SKILL.md` exits 0. Fix violations before `sync-skills.sh`.

Process

1. **Gather requirements** — ask user about:

• What task/domain does the skill cover?
• Which use cases must the skill handle?
• Does it need executable scripts or just instructions?
• Any reference materials to include?
• What specs/ output does it produce (if any)?

2. **Verify Principles** — Ensure the skill aligns with [PRINCIPLES.md](../../docs/PRINCIPLES.md):

• Is it atomic (verb-noun)?
• Is it "deep" (simple interface, complex internal logic)?
• Does it include Hard Gates?
• Is it verifiable with a `.feature` file?

3. **Draft the skill** — create:

• SKILL.md with concise instructions (see [REFERENCE.md](REFERENCE.md) for template)
• Additional reference files if content exceeds 100 lines
• Utility scripts if deterministic operations needed

**Auto-skill from library README:** When user provides a library README or API docs URL, extract triggers and HARD GATEs. Draft verify commands and specs/ output into SKILL.md. Do NOT invent APIs not in the source.

4. Add `model:` frontmatter (`haiku` | `sonnet` | `opus`) per [model-profiles.md](../../docs/references/model-profiles.md).

> **STREAM CONTINUITY** — When writing file content, output in continuous chunks of ~200 lines. Do not pause. Continue immediately until complete. If you need time, emit a placeholder comment rather than going silent.

5. **Review with user** — present draft and ask:

• Does this cover your use cases?
• Anything missing or unclear?
• Does any section need more or less detail?

6. **Completion-honesty gate (HARD GATE — e45s02)** — Before declaring done:

• Run `bash scripts/validate-skill-description.sh skills/<name>/SKILL.md` — must exit 0
• Run `bash scripts/validate-agentic-ste.sh --strict skills/<name>/SKILL.md` — must exit 0 (e79s02)
• Run `bash scripts/sync-skills.sh` — must complete without error
• Run `bash scripts/run-skill-verify.sh <name>` if the skill defines a verify command
• Show terminal output for each — narration without evidence is rejected

Naming Rules

Every skill name must be a **two-word verb-noun pair**. See [REFERENCE.md](REFERENCE.md) for full rules, examples, and documented exceptions.

specs/ Output

If the skill produces written output, it goes in `specs/` at the project root. Document the output file path in the skill body and in CONVENTIONS.md's output files table.

Review Checklist

After drafting, verify:

• [ ] Name is a two-word verb-noun pair (or follows grill-me exception)
• [ ] Description < 1024 chars, triggers only, no workflow-summary leakage
• [ ] Description includes triggers ("Use when...")
• [ ] SKILL.md under 100 lines
• [ ] No time-sensitive info
• [ ] Consistent terminology with CONVENTIONS.md
• [ ] specs/ output documented if applicable
• [ ] `validate-skill-description.sh` exits 0
• [ ] `validate-agentic-ste.sh --strict` exits 0 (e79s02)
• [ ] `sync-skills.sh` run to propagate to Cursor/Gemini
• [ ] `bash scripts/validate-skill-catalog.sh` passes for the new skill (HARD GATE — completion honesty)

> **HARD GATE** — Do NOT declare the skill done until `bash scripts/validate-skill-catalog.sh --strict --skill <name>` exits 0. Validator enforces verb-noun name, HARD GATE block, description ≤1024 chars, and `→ verify:` command.

Verify

→ verify: `bash scripts/validate-skill-catalog.sh --strict --skill craft-skill && bash scripts/validate-skill-description.sh skills/craft-skill/SKILL.md`