CONCEPT Cited by 1 source

MCP Server Card¶

Definition¶

MCP Server Card is a draft well-known JSON document that describes a Model Context Protocol server before an agent connects to it. Published at /.well-known/mcp/server-card.json on the host that serves the MCP server.

Draft standard; currently tracked at modelcontextprotocol/modelcontextprotocol #1649.

Shape¶

{
  "$schema": "https://static.modelcontextprotocol.io/schemas/mcp-server-card/v1.json",
  "version": "1.0",
  "protocolVersion": "2025-06-18",
  "serverInfo": {
    "name": "search-mcp-server",
    "title": "Search MCP Server",
    "version": "1.0.0"
  },
  "description": "Search across all documentation and knowledge base articles",
  "transport": {
    "type": "streamable-http",
    "endpoint": "/mcp"
  },
  "authentication": {
    "required": false
  },
  "tools": [
    {
      "name": "search",
      "title": "Search",
      "description": "Search documentation by keyword or question",
      "inputSchema": {
        "type": "object",
        "properties": { "query": { "type": "string" } },
        "required": ["query"]
      }
    }
  ]
}

An agent can read this static file, decide "yes, this MCP server's search tool fits what I need", obtain the tool schema, and connect to the transport endpoint — all without making a protocol call.

Why pre-connect discovery matters¶

MCP's primary discovery mechanism is "connect, then list_tools" — which requires an active session, authentication negotiation, and protocol compliance on both sides. For an autonomous agent evaluating many MCP servers, that's a heavy- weight primitive.

MCP Server Card is a lightweight catalog-like file the agent can slurp via one HTTP GET, parse, and filter on before committing to a session. Analogous to an API Catalog but for MCP servers and agents rather than classical HTTP APIs and human developers.

Adoption (2026-04)¶

Fewer than 15 sites across the top 200 k domains combined for MCP Server Card + API Catalog (Radar). Draft-standard stage; expected uptake with MCP ecosystem growth.

Self-referential example¶

isitagentready.com publishes its own MCP Server Card at https://isitagentready.com/.well-known/mcp.json (slight variation on the draft-standard path) exposing a scan_site tool over Streamable HTTP — an MCP-compatible agent can use isitagentready to audit other sites without ever loading the web UI.

Seen in¶

sources/2026-04-17-cloudflare-introducing-the-agent-readiness-score-is-your-site-agent-ready — canonical wiki instance. Checked by the Agent Readiness Score under Agent Actions.

systems/model-context-protocol — parent protocol this card describes.
systems/mcp-server-card — wiki system page.
concepts/api-catalog — sibling discovery primitive for classical HTTP APIs.
concepts/well-known-uri — substrate convention.
concepts/agent-readiness-score — where this is graded under Agent Actions.
patterns/well-known-endpoint-discovery — umbrella pattern.