Guides for MCP server builders

• I asked Claude, Codex and Gemini the same question 500 times

  Measured call rates for one MCP tool: alone, among 32 tools, with an obscure name, and against built-in web search.

• Why Claude isn't calling your MCP tool

  Your server works, but the tool never fires. Six causes, in the order to check them, with measured call rates.

• How to test an MCP server

  A server can pass every protocol test and still never get called. Four layers of testing, with the commands.

• MCP analytics: what your logs can and can't show

  What a server can observe, what it cannot, and how to see the calls that never happened.