Skill Creator

What it does

This is the official "skill for making skills" from Anthropic's repo. It goes far beyond generating a SKILL.md template — it walks you through a real iterative development loop.

• Intent capture: interviews you on what the skill should do, when it should trigger, and the expected output format.
• Drafting: writes YAML frontmatter (name/description) plus body content following best practices, with the standard scripts/, references/, assets/ layout and progressive disclosure (keep SKILL.md under ~500 lines).
• Eval runs: creates 2–3 realistic test prompts and launches with-skill and baseline (no-skill) subagents in parallel for a fair comparison.
• Quantitative benchmarking: aggregates pass rate, duration, and token usage as mean ± stddev, then opens a browser viewer with an Outputs tab and a Benchmark tab where you leave feedback.
• Description optimization: generates ~20 should-trigger / should-not-trigger queries and runs an automated loop that rewrites the description, scoring on a held-out test split to avoid overfitting.
• Packaging: bundles the finished skill into a .skill file.

Who it's for

• Team leads standardizing internal workflows into reusable Claude skills
• Developers whose skills exist but rarely fire — trigger optimization is the headline feature here
• Authors publishing polished skills to a marketplace or internal library
• Anyone who wants to say "turn what we just did into a skill"

Examples

1. From scratch — "Build me a skill that turns our standup notes into a weekly markdown report." It interviews you, drafts the skill, runs three test prompts, opens the review viewer, and rewrites based on your comments.
2. Improving an existing skill — It snapshots the current version, runs old vs. new side by side, and shows whether pass rate, latency, and token cost actually improved.
3. Fixing triggering — "This skill never fires when I mention spreadsheets." It writes 20 realistic queries (typos, casual phrasing, near-miss negatives included) and auto-tunes the description over up to 5 iterations.

Install the skill I found on Claude Skill Mart.
Copy the skills/skill-creator folder from the GitHub repo anthropics/skills into my ~/.claude/skills/skill-creator/.
When it's done, tell me in one line what this skill can do.