skill-creator

Skill Creator

You are about to write or edit a skill another Claude will load. A skill is a directory with a SKILL.md. Frontmatter is metadata for the trigger decision; the body is a prompt that enters the conversation when the skill fires and stays for the rest of the session. This skill is the playbook for picking the right shape, writing the frontmatter, structuring the body, and shipping bundled references and scripts that survive plugin install.

Target is Opus 5. Same rules work for Sonnet 5 at lower cost and for Haiku 4.5, which supports no effort parameter at all. The body of every skill you produce here is a prompt, route that body work through the sibling ac:prompt-writer skill instead of restating prompt principles here.

Two jobs, not one

Writing a skill splits cleanly into two tasks, and conflating them is the most common authoring mistake.

1. Skill shape. Frontmatter, file layout, scope, invocation control, bundling. This file teaches that.
2. Body content. The markdown the model reads when the skill triggers. This is a prompt. Route through ac:prompt-writer (architecture, snippets, anti-patterns, Opus 5 tuning).

The shape decisions front-load most of the leverage. A great body inside the wrong shape (wrong scope, wrong invocation control, bloated description) never gets used. A modest body inside the right shape gets used every day.

Decision flow

Route by the user's request. Each branch lands on the right reference for the depth.

Is a skill the right tool at all?
├── Single fact that never changes → CLAUDE.md, route through `ac:claude-md-rules-creator`. Not a skill.
├── Truly one-off task → just do it. Not a skill.
├── Determinism that the body cannot guarantee → hook, not skill. Route through `update-config`.
├── Cross-cutting persona, isolated context → custom agent, route through `agent-creator` if available.
└── Recurring playbook, procedure, or knowledge → SKILL is the right tool, continue.

Is it user-driven `/name [args]` with arguments, often `disable-model-invocation: true`?
├── YES → use this skill for shape, then specialize through `command-creator` if available
│         (argument design, shell injection, built-in command patterns).
└── NO  → continue with this skill alone.

Is this an audit or fix of an existing skill?
├── YES → `${CLAUDE_SKILL_DIR}/references/anti-patterns.md` first, then
│         `${CLAUDE_SKILL_DIR}/references/claude-code-mechanics.md` if behavior is unclear.
└── NO  → walk the Workflow below.