What Is MCP
Model Context Protocol (MCP) is a standard protocol for AI agents to connect to external tools/data sources. Proposed by Anthropic in 2024, with many clients/servers published from 2025.
Why a Standard Was Needed
Each LLM vendor had its own Tool Use, Function Calling spec, requiring per-vendor implementation per tool. MCP is, like USB-C, a standard where "make once, use on multiple clients."
3 Kinds of Capability
Tools
Functions the LLM can call. E.g., "SELECT on a database," "file write," "external API call."
Resources
Data the LLM can read. E.g., "file list," "latest log," "DB schema."
Prompts
Reusable prompt templates. E.g., "code-review checklist," "minutes template."
