Mcp

I shipped rihla — a flight-search MCP server — to GitHub, PyPI, and the official MCP registry in a single day. The mechanical steps went exactly as planned. The one thing that didn’t was the thing no schema could have told me: a server.json that validates perfectly can still describe an install that doesn’t work. Here’s the trap, the fix, and three smaller ordering gotchas that are cheap to avoid and expensive to discover after upload. ...

I built an MCP server that searches flights across flexible dates and multiple airports, then used it for an actual trip I was planning. Three tool calls in, it had produced a correct answer, and along the way had wasted most of a day’s API quota and told the agent several things that weren’t true. None of the four problems was a crash. Every one of them was a shape problem: the output was well-formed, plausible, and misleading. That’s the failure mode that matters when your consumer is a language model, because an agent can’t smell that a number is wrong. It acts on whatever you hand it — and when the number is wrong in an expensive direction, it acts again. ...