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name: skill-builder description: Create or update Codex Skills (SKILL.md). Use when asked to make/update a skill, add SKILL.md, skill template, or mentions Codex skills / Agent Skills / スキル作成. metadata: short-description: Create/update Codex skills

Goal

• Design and create a small, triggerable, safe Codex Skill.

Inputs (ask only if missing)

• Purpose: what task the skill should help with (one sentence).
• Trigger situations/keywords (Japanese/English).
• Scope: repo-local (.codex/skills/) or user-wide (~/.codex/skills/).

Design principles

• One skill = one job (single responsibility).
• description is the trigger surface:
  • Keep it single-line, concise.
  • Include: "Use when ..." + concrete keywords.
• Keep SKILL.md short:
  • Goal / Inputs / Steps / Output format / Edge cases / Trigger examples.
  • Long details go to references/ instead of bloating the body.
• If the skill feels wrong during use, fix it immediately (minimal change).

Steps

1. Pick a kebab-case name (1–64 chars) and create the folder with the same name.
2. Write a single-line description that:
   • States when to use the skill
   • Contains 4–10 trigger keywords (terms users actually say)
3. Draft the SKILL.md sections:
   • Goal
   • Inputs (ask only if missing)
   • Non-goals / Guardrails
   • Steps (commands or deterministic process)
   • Output format (exactly what to return)
   • Edge cases
   • Trigger examples (2–6)
4. Check overlap:
   • If it overlaps with existing skills, split or narrow description.
5. (Optional) If scripts are required:
   • Put them under scripts/
   • Document usage, dependencies, and failure modes clearly.
   • Otherwise keep instruction-only.

Output format

• File path(s) created/updated.
• Short explanation of triggers and what the skill will do.
• Any open questions (only if truly required).

Trigger examples

• "skills を作って"
• "SKILL.md を追加して"
• "Agent Skills のテンプレ作って"
• "この作業をスキル化したい"