Iterative loop for building skills: draft, run Claude with the skill on test prompts, evaluate qualitatively and quantitatively with an eval viewer, and rewrite. Also optimizes the description for trigger accuracy.
What it does
Where skill-creator runs and what it adds, from its documentation
Drafts new skills from scratch
Runs test prompts and evals, including variance benchmarking
Generates a review page via eval-viewer/generate_review.py
Optimizes SKILL.md descriptions for triggering
When to use it
Good fit
Authoring a new skill
Improving or measuring an existing skill
Not for
Building plugins with hooks or MCP (see plugin-dev)
How to install skill-creator
Register the marketplace in Claude Code: /plugin marketplace add anthropics/skills
Install the bundle that contains it (document-skills or example-skills): /plugin install example-skills@anthropic-agent-skills
Or copy the skill folder to ~/.claude/skills/skill-creator/ (personal) or .claude/skills/skill-creator/ (project)
Mention the task in a prompt; Claude loads the skill automatically when the SKILL.md description matches
Permissions and security
What it can access
Instructions loaded into Claude's context; any scripts it bundles run through Claude Code's normal tool permissions (shell, file edits)
Security notes from the maintainers
Anthropic repo disclaimer: skills are provided for demonstration and educational purposes; behavior in Claude may differ
Review the source before granting an agent access to credentials or production systems. We document what the maintainers state; we do not audit code.
Limitations
Repo README says implementations are examples and may differ from what Claude.ai provides
How do I install the skill-creator skill in Claude Code?
Add the marketplace with /plugin marketplace add anthropics/skills and install the bundle containing it, or copy skills/skill-creator into ~/.claude/skills/. source
When does Claude use the skill-creator skill?
Claude loads it automatically when the request matches the description field in its SKILL.md frontmatter. source
Is the skill-creator skill official?
Yes, it is published in Anthropic's anthropics/skills repository. source
