TL;DR: An MCP registry is a centralized catalog of MCP servers - what they do, how to connect, what tools they expose, and who's authorized to call them. Without one, every developer and agent maintains their own copy of that information, credential rotation breaks everything, and access control is nonexistent. With one, tool discovery is dynamic, credentials are managed centrally, and RBAC governs what each agent can see and call. This post covers what it is, how it works, and the specific fai...