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-optimizerSKILL.md
Prompt Optimizer
Systematically improve Mycelium instructions through measurement. Adapted from n-trax.
Commands
baseline -- Capture current performance
- Run
/mycelium:eval-runner run-split optimization— record as optimization scores - Run
/mycelium:eval-runner run-split holdout— record as holdout scores - 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
- Read variant from
.claude/optimization/variants/<variant>.md - Apply the CLAUDE.md changes described
- Run
/mycelium:eval-runner run-split optimization— this is the hill-climbing signal - Run
/mycelium:eval-runner run-split holdout— this validates generalization - Store results in
.claude/optimization/results/<variant>.json - Compare against baseline. Flag overfitting if optimization improves but holdout degrades.
- Do NOT auto-revert -- let user decide
report -- Compare all variants
Generate comparison table with split-aware columns:
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
- Capture baseline
- Hypothesize an instruction improvement
- Document in variants/ directory
- Test the variant
- Compare via report
- Keep or revert based on data
- 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
- SKILL.md in the repositoryCheckingplugins/mycelium/skills/prompt-optimizer/SKILL.md
Popularity
- 7-day trend score
- 5
Not refreshed yet.
Works with
Any agent vskill installs to: 56 targets in all. These 39 have a page on this site.
- Claude Code
- Cursor
- GitHub Copilot
- Windsurf
- Codex
- Gemini CLI
- Cline
- Amp
- Roo Code
- Goose
- Continue
- Kilo Code
- Junie
- Trae
- OpenHands
- Qwen Code
- AI Agent
- Tabnine Chat
- Sourcegraph Cody
- Amazon Q
- Firebase Genkit
- Sweep
- Devin
- Phind
- Mentat
- Claude Desktop
- Aider
- GPT Pilot
- Plandex
- bolt.new
- v0
- Replit Agent
- Anse
- TypingMind
- BetterChatGPT
- LibreChat
- Warp AI
- Pieces
- Fig AI
Embed badge
[](https://verified-skill.com/skills/haabe/mycelium/prompt-optimizer)