I spent the early part of this year doing the thing everyone does when they discover the Model Context Protocol: I installed everything. Filesystem, git, GitHub, Postgres, SQLite, a web fetcher, two search servers, a browser automation server, a memory server, and a handful of niche ones I no longer remember. My Claude Code config looked like a Christmas tree. And for about a week it felt powerful — the agent could touch everything. Then I started reading my own context windows, and the feeling curdled. Before the agent had read a single line of my code, something like a fifth of the context was already gone, eaten by tool schemas describing capabilities the agent would never use in that session. I had built a kitchen sink and was paying rent on every faucet. This guide is the correction. After running coding agents — Claude Code mostly, with stints in Cursor, Cline, and Goose — against real work for months, I have a short list of MCP servers that consistently earn their keep, organized by category.…