The MCP (Model Context Protocol) ecosystem now has over 14,000 servers. Most of them you do not need. Installing too many slows responses, inflates your context window with tool definitions that never get used, and turns debugging into a guessing game across a dozen integrations. This guide applies a simple filter: only install a server if it replaces a daily copy-paste workflow. It is organised by role — developers, QA testers, and DevOps/platform engineers — because the right stack is different for each.