MCP is a protocol layer that decouples tools from providers

MCP standardizes how agents discover and call external tools (see: code intelligence replaces dozens of grep calls with one graph query), replacing bespoke per-model function-calling adapters. Any host that speaks MCP connects to any server, regardless of the underlying model. Migrating from 47 custom wrappers to 6 MCP servers cut integration deploy time from three days to eleven minutes.

The three primitives cover most agent needs: resources (read-only data snapshots), tools (executable actions with typed schemas), and prompts (reusable templates). A single host maintains multiple client connections to different servers, giving the underlying model a unified tool surface. The model does not know whether a tool call hits a local SQLite database or a remote AWS Lambda; it just sees standardized capabilities. This abstraction is what lets the ecosystem grow without each agent reimplementing integrations.