MCP Script Rules When working with files in scripts/ : DO Use CLI arguments for all parameters (argparse) Include USAGE docstring at top of file Use call mcp tool("server tool", params) pattern Handle errors gracefully with informative messages Print results to stdout for Claude to process DON'T Hardcode parameters in the script Edit scripts to change parameters (use CLI args instead) Import from servers/ directly (use runtime.mcp client) Tool Naming Tool IDs use double underscore: serverName toolName Examples: morph warpgrep codebase search ast grep ast grep perplexity perplexity ask Testing Test with: uv run python m runtime.harness scripts/<script .py help

mcp-scripts