Build a `BaseTool[InSchema, OutSchema]` subclass — input/output schemas, `BaseToolConfig`, `run()` (and optional `run_async()`), env-driven secrets, typed failure outputs. Use when the user asks to "add a tool", "create a tool", "wrap an API as a tool", "build a `BaseTool`", "make a calculator/search/weather tool", or runs `/atomic-agents:create-atomic-tool`.
Install
npx skills add Eigenwise/atomic-agents --skill create-atomic-toolnpx skills add Eigenwise/atomic-agents --skill create-atomic-tool -a claude-code -gnpx skills add Eigenwise/atomic-agents --skill create-atomic-tool -a codex -ggemini skills install https://github.com/Eigenwise/atomic-agents.git --path claude-plugin/atomic-agents/skills/create-atomic-toolgh skill install Eigenwise/atomic-agents create-atomic-toolgit clone --depth 1 https://github.com/Eigenwise/atomic-agents /tmp/Eigenwise__atomic-agents
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/Eigenwise__atomic-agents/claude-plugin/atomic-agents/skills/create-atomic-tool ~/.claude/skills/create-atomic-tool # Claude Code
cp -R /tmp/Eigenwise__atomic-agents/claude-plugin/atomic-agents/skills/create-atomic-tool ~/.agents/skills/create-atomic-tool # Codex, Cursor, Gemini CLI, Copilot, OpenCode