Definition
An open protocol for connecting LLMs to external data sources and tools through a standard interface.
In practice
Anthropic introduced MCP to standardize how an agent 'plugs into' a CRM, a calendar, a knowledge base, etc. Rather than re-implementing tool integrations for every agent framework, you build an MCP server once and any MCP-compatible agent can use it. Adoption is growing across Claude Desktop, IDEs, and increasingly third-party agent platforms.