Evaluate Skill

Evaluate Skill

Use this skill when the target is a local skill directory or a SKILL.md file. cc-plugin-eval handles the structural and budget signals deterministically without an LLM. If the user wants an LLM-graded rubric or a rewrite pass, hand off to the skill-creator skill (Anthropic's skill-creator@claude-plugins-official) - that skill specializes in single-skill grading and rewrites, while cc-plugin-eval focuses on structural and budget signals.

The runnable commands below invoke the shipped script through the plugin root, which works in any checkout: node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" <command> <args>. Inline mentions of cc-plugin-eval <command> are shorthand for that same invocation; the bare cc-plugin-eval alias only exists if you ran npm link in the plugin directory.

Workflow

1. Treat "Evaluate this skill." as the default entrypoint.
2. If the user names a skill instead of giving a path, resolve it locally first. Prefer ~/.claude/plugins/cache/<plugin-id>/skills/<skill-name> for installed-plugin skills, then any repo-local skills/<skill-name> directory. If the name is still ambiguous, ask one short clarifying question before running commands.
3. If the user says the request in natural language first, run cc-plugin-eval start <skill-path> --request "<user request>" --format markdown to show the routed path clearly.
4. Run cc-plugin-eval analyze <skill-path> --format markdown. The convenience alias cc-plugin-eval evaluate-skill <skill-path> returns the same payload but errors out if the path is not a skill.
5. Review At a Glance, Why It Matters, Fix First, and Recommended Next Step before drilling into details.
6. Explain which findings are structural (frontmatter validity, file size, broken links), which are budget-related (trigger / invoke / deferred), and which are best-practice (allowed-tools syntax, progressive disclosure).
7. If the user asks for an "analysis" of the skill, do not stop at the report. Also run cc-plugin-eval init-benchmark <skill-path> and show the setup questions for refining the starter scenarios in .cc-plugin-eval/benchmark.json.
8. If the user wants real usage numbers, switch to "Measure the real token usage of this skill." and run the benchmark flow.
9. After observed usage is available, use cc-plugin-eval measurement-plan <skill-path> --observed-usage <usage.jsonl> --format markdown to recommend what to instrument next.
10. If the user wants a rewrite plan, route to ../improve-skill/SKILL.md. That skill writes a brief and hands it to skill-creator for the actual rewrite.

Skill-Specific Priorities

• frontmatter validity (CC213) and the Claude allowed-key set (name, description, when_to_use, argument-hint, arguments, disable-model-invocation, user-invocable, allowed-tools, model, effort, context, agent, hooks, paths, shell, license, metadata)
• name and description quality (CC201, CC202, CC203, CC204, CC205, CC206)
• progressive disclosure thresholds: >350 lines (CC208), >500 lines (CC210), >800 lines (CC209)
• broken relative links and supported URI schemes (CC211): allow-list includes claude://, app://, plugin://, rules://, mailto:, http://, https://, #
• oversized SKILL.md or descriptions
• allowed-tools syntax (CC215): Claude tool names are PascalCase (Bash, Read, Edit, Skill, mcp__server__tool); strings should be space-separated or YAML lists, not comma-separated
• explicit disable-model-invocation: true on task-style skills (CC216) where automatic invocation would be wrong
• helper script quality for TypeScript and Python files

Chat Requests To Recognize

• Evaluate this skill.
• Give me an analysis of this skill.
• Audit this skill.
• Why did this skill score that way?
• What should I fix first?
• This skill is too big.
• This skill is not triggering.
• Measure the real token usage of this skill.

Commands

node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" start <skill-path> --request "Evaluate this skill." --format markdown
node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" analyze <skill-path> --format markdown
node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" evaluate-skill <skill-path> --format markdown
node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" explain-budget <skill-path> --format markdown
node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" measurement-plan <skill-path> --format markdown
node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" init-benchmark <skill-path>
node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" benchmark <skill-path>
node "${CLAUDE_PLUGIN_ROOT}/scripts/cc-plugin-eval.js" analyze <skill-path> --observed-usage <usage.jsonl> --format markdown

Reference

• ../../references/chat-first-workflows.md
• ../../references/component-validators.md