Building with MCP servers is both fun and a bit chaotic. The official MCP spec keeps evolving, but agents aren't always quick to catch up, and it isn't always obvious where the gaps are. This talk is part commiseration, and part survival guide. I'll share what we've learned the hard way: from designing tools agents actually use, to experimenting when client support falls short. In a space moving this quickly, hacking and experimenting are our new \"first principles.\"