Field notes from inside the room.

What we learn running real agents against real MCP servers, CLIs and APIs. Every number comes with the agent version and the date.

16 October 2026
How to optimise your MCP tools by knowing how agents call them
Refused results, 63k-token tool lists, tools not found, 12.7k-token errors: what we measured on a 99-tool production MCP server, how Claude Code, Codex, Grok Build and OpenCode call tools, and the fixes ranked by impact.