1. Introduction
1. Introduction
Section titled “1. Introduction”1.1 Purpose
Section titled “1.1 Purpose”The MCP Description Specification defines a standard format for describing the capabilities of a Model Context Protocol (MCP) server as a static, curated document.
The MCP ecosystem supports runtime discovery and capability inspection. While effective for dynamic interactions, runtime discovery alone limits offline tooling, cross-platform interoperability, design review, and governance workflows.
This specification addresses these limitations by providing a portable description format for MCP servers, analogous to the descriptive role OpenAPI plays for HTTP APIs.
1.2 Goals
Section titled “1.2 Goals”An MCP Description document enables:
- Standardized server descriptions — a consistent structure for declaring server metadata, transports, tools, resources, prompts, and capabilities.
- Offline discoverability — platforms can index and display server capabilities without establishing a runtime connection.
- Tooling interoperability — documentation generators, testing frameworks, agent discovery tools, IDE integrations, and governance platforms can operate on a common format.
- Description-driven development — teams can define, review, and validate MCP server surfaces before deployment.
1.3 Audience
Section titled “1.3 Audience”This specification is intended for:
- MCP server developers who publish capability descriptions
- MCP client and agent developers who consume server descriptions
- Platform developers building registries, documentation portals, and governance tools
- Tool authors creating validators, generators, and IDE integrations
1.4 Relationship to the MCP Protocol
Section titled “1.4 Relationship to the MCP Protocol”The MCP Description Specification does not replace the MCP protocol. It complements the protocol by providing a static description format for server capabilities.
| MCP Protocol | MCP Description |
|---|---|
| Runtime communication | Static declaration |
| Discovery and runtime metadata | Server metadata and declared protocol coverage |
| Tool invocation | Tool definitions |
| Resource fetching | Resource definitions |
The MCP protocol defines runtime communication and behavior. An MCP Description statically represents durable, externally relevant server semantics without reproducing MCP wire choreography.
1.5 Scope
Section titled “1.5 Scope”This specification defines:
- The structure and semantics of an MCP Description document
- JSON Schema validation rules for MCP Description documents
- The specification extension mechanism for vendor-specific metadata
This specification does NOT define:
- The MCP protocol itself
- Runtime behavior of MCP servers or clients
- The content or structure of vendor extensions (these are defined independently by extension authors)