Skill Eval

Skill Eval

Orchestrate the full evaluation lifecycle for agentskills.io skills.

Quick start

Agent: "eval my-new-skill"

The agent authors 3-5 test cases, scaffolds a workspace, runs with-skill and without-skill baselines, grades outputs, and produces a benchmark report.

Workflows

1. Author test cases

1. Read target skill SKILL.md. Extract capabilities and constraints.
2. Load references/test-quality-checklist.md.
3. Generate 3-5 test cases. Cover normal prompt, edge case, and malformed input.
4. Write test cases to <target-skill>/evals/evals.json. Conform to assets/evals-schema.json. Produce JSON with keys skill_name, evals[]. Each eval has id, prompt, expected_output, optional files[].
5. Create input fixture file at <target-skill>/evals/evals.json.
6. Validate evals.json against the test quality checklist. Fix flagged items.

2. Scaffold workspace

7. Run scripts/scaffold-workspace.sh <workspace-dir> <iteration-N> <evals-json>. Script creates per-eval with_skill/outputs/ and without_skill/outputs/ directories.
8. Copy current skill directory to <workspace-dir>/skill-snapshot/. Overwrite existing snapshot.

3. Execute eval runs

9. Read references/grading-prompt-template.md.
10. Spawn a subagent for each with_skill run. Pass skill directory in skill snapshot path, test prompt, input files, and output directory.
11. Save with_skill/timing.json on each subagent return.
12. Spawn a subagent for each without_skill run. Same prompt, no skill path.
13. Save without_skill/timing.json on each subagent return.
14. Verify every eval directory has output files in both with_skill/outputs/ and without_skill/outputs/.

4. Grade outputs

15. Run scripts/grade-assertions.sh <output-dir> <assertions-file>. Script checks deterministic assertions. Returns partial grading JSON with PASS/FAIL and evidence.
16. Spawn a grading subagent for remaining assertions. Pass outputs and assertion text. Require concrete evidence per result.
17. Save grading results to <eval-dir>/<config>/grading.json.

5. Aggregate benchmarks

18. Run scripts/aggregate-benchmark.sh <workspace>/iteration-N. Compute mean pass rate, token count, and duration. Write delta to benchmark.json.
19. Read references/eval-readiness-checklist.md. Apply scoring guide (0–100% bands) to current eval setup. Record maturity band in benchmark report.
20. Read assets/eval-report-template.html. Fill template variables with benchmark data. Include {{JSON_SUMMARY}} — compact JSON object at top of report for machine parsing. JSON schema:

    { skill, iteration, report_date, eval_count,
      readiness: { score, total, band },
      delta: { pass_rate, tokens, time },
      with_skill: { pass_rate, stddev, samples, tokens, time },
      without_skill: { pass_rate, stddev, samples, tokens, time },
      evals: [{ id, pass_rate, assertions: [{id, pass, evidence}] }],
      patterns: [{ type, count, action }],
      fixes: [{ priority, description }]
    }
    

    Contract rule: iteration must be string in form iteration-N (e.g., iteration-5).
21. Write report to <target-skill>/<skill-name>-iteration-N-eval-report.html.

6. Analyze patterns

22. Read references/iteration-playbook.md.
23. Classify assertions: always-pass, always-fail, skill-dependent, inconsistent.
24. Review execution transcripts for failed evals. Locate skipped instructions and wasted steps.

7. Produce improvement recommendations

25. Collect failure signals: failed assertions, human feedback, transcript patterns.
26. Generate improvement prompt. Format as YAML with skill_path, iteration, benchmark_delta, and changes[] array. Each change has type, section, reason, suggestion.
27. Print improvement prompt for user to feed into downstream skills.
28. On user confirmation, loop to step 7 with new iteration number.

Reference files

See grading-prompt-template.md for LLM judge dispatch prompt. See blind-compare-prompt.md for blind comparison scoring. See test-quality-checklist.md for test case quality review criteria. See eval-readiness-checklist.md for eval setup scorecard (pre-run self-diagnostic). See workspace-layout.md for eval workspace directory structure. See iteration-playbook.md for iteration analysis guidance. See eval-report-template.html for the HTML report template.