What MCP Solves and What It Deliberately Does Not.

MCP is one of the most thoughtfully scoped technical standards to come out of the AI ecosystem. That scope is intentional. Understanding exactly where MCP stops is the precondition for understanding what needs to be built on top of it. This post is about that boundary. What MCP actually does MCP is a JSON-RPC 2.0 protocol that defines three primitives a server can expose: tools, resources, and prompts. It turns the N x M integration problem between LLM applications and external tools into N + M.