Create a new skill or improve an existing one with an eval loop: write test cases first, run the skill, grade the outputs with assertions, compare against the previous iteration as the baseline, generalise the rule rather than patching the case, and promote when a run is clean.
Install
npx skills add JamsusMaximus/growth-agents --skill skill-iteratornpx skills add JamsusMaximus/growth-agents --skill skill-iterator -a claude-code -gnpx skills add JamsusMaximus/growth-agents --skill skill-iterator -a codex -ggemini skills install https://github.com/JamsusMaximus/growth-agents.git --path skills/skill-iteratorgh skill install JamsusMaximus/growth-agents skill-iteratorgit clone --depth 1 https://github.com/JamsusMaximus/growth-agents /tmp/JamsusMaximus__growth-agents
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/JamsusMaximus__growth-agents/skills/skill-iterator ~/.claude/skills/skill-iterator # Claude Code
cp -R /tmp/JamsusMaximus__growth-agents/skills/skill-iterator ~/.agents/skills/skill-iterator # Codex, Cursor, Gemini CLI, Copilot, OpenCode