The Model Context Protocol is the open specification for how a language model’s harness talks to an external tool server — connecting an agentic workflow to filesystems, APIs, databases, and other tools without bespoke per-integration code. MCP standardizes the wire format (JSON-RPC over stdio or HTTP), the tool-discovery handshake, and the shape of tool calls and results, so the same server works across any compliant harness.
This page is a stub. The protocol shows up in this section as the substrate beneath AI plugins — a Claude Code plugin frequently bundles one or more MCP servers, and the context-cost characteristics of MCP tools are what make plugin selection consequential.