updating-mcp-tools

The workflow for writing or changing YAAC's MCP tool definitions in src/yaac/frontend.py. Use whenever a tool is added, removed or renamed, a docstring, parameter or Field description is edited, or the server instructions change — even for a small wording tweak: first get the descriptions right, then regenerate docs/tools.md so the documented toolset matches what a client sees. Also use when docs/tools.md is…