An MCP server is the implementation of the Model Context Protocol on the side of the external tool, service, or data source that an AI model or agent wants to interact with. The MCP server exposes a governed, structured interface for AI systems to discover capabilities, request context, and perform actions according to agreed security and governance rules.

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Purpose:

While MCP defines how AI models and tools communicate, the MCP server is the tool’s entry point into that ecosystem. It translates MCP requests into real actions (such as fetching data, running a query, or triggering a workflow) and ensures that all activity complies with the organization’s access policies and security requirements.

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Key Functions:

• Capability Advertisement — Tells connected AI systems what actions and data are available (and under what conditions).
• Context Delivery — Supplies relevant data or state information to the AI model within security boundaries.
• Action Execution — Carries out tasks or workflows requested by the AI model, if authorized.
• Security Enforcement — Applies authentication, authorization, and policy controls to all requests.
• Audit & Logging — Tracks all interactions for compliance, monitoring, and incident response.

Example:

If an enterprise document repository runs an MCP server, an AI agent could connect through MCP, search for documents containing specific keywords, retrieve summaries, and insert them into a report — all while the server ensures the agent only accesses files it’s permitted to see.

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Security Considerations:

• Implement least-privilege access for all agent interactions.
• Require strong authentication for connecting AI agents.
• Log all requests and responses for auditability.
• Apply rate limiting and input validation to prevent abuse or prompt injection attacks.

Related terms:

• Model Context Protocol (MCP) – The underlying standard defining communication between MCP clients and servers.
• MCP Client – A software component that connects to MCP servers to securely discover, request, and use tools or data following the Model Context Protocol.