haabe/mycelium/prompt-optimizer

Claude Code and agent skill by haabe/mycelium

Trust tier 3
  • community
Source check pending

Checking that the SKILL.md file is still in the repository.

A/B test CLAUDE.md instruction changes against eval benchmarks. Capture baselines, test variants, compare results.

Install

npx vskill@latest install haabe/mycelium/prompt-optimizer

SKILL.md

Prompt Optimizer

Systematically improve Mycelium instructions through measurement. Adapted from n-trax.

Commands

baseline -- Capture current performance
  1. Run /mycelium:eval-runner run-split optimization — record as optimization scores
  2. Run /mycelium:eval-runner run-split holdout — record as holdout scores
  3. Record both to .claude/optimization/baseline.json: timestamp, CLAUDE.md hash, optimization metrics, holdout metrics, overall and per-category metrics
test <variant> -- Test a variant
  1. Read variant from .claude/optimization/variants/<variant>.md
  2. Apply the CLAUDE.md changes described
  3. Run /mycelium:eval-runner run-split optimization — this is the hill-climbing signal
  4. Run /mycelium:eval-runner run-split holdout — this validates generalization
  5. Store results in .claude/optimization/results/<variant>.json
  6. Compare against baseline. Flag overfitting if optimization improves but holdout degrades.
  7. Do NOT auto-revert -- let user decide
report -- Compare all variants

Generate comparison table with split-aware columns:

| Variant | Opt Pass Rate | Holdout Pass Rate | Delta Opt | Delta Holdout | Overfit? | Decision |

Flag Overfit? = YES when optimization delta is positive but holdout delta is negative.

exemplar <eval-name> -- Capture winning trajectory

After a clean eval win (1 iteration, fast), save the approach to .claude/optimization/exemplars/.

Workflow

  1. Capture baseline
  2. Hypothesize an instruction improvement
  3. Document in variants/ directory
  4. Test the variant
  5. Compare via report
  6. Keep or revert based on data
  7. Capture exemplars from clean wins

Security

  • Security scanPassed, 95 of 100Pattern checks on the skill's files.
  • Model reviewPassed

Quality evaluation

  • Task evaluationNot runNo evaluation yet. Run one in Skill Studio.

Source

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