MCP Server Card exists

agent_protocol_mcp_server_card

Checks if an MCP Server Card is published for agent discovery.

What does this rule check?

An MCP (Model Context Protocol) Server Card at /.well-known/mcp/server-card.json declares your site's MCP capabilities — including server info, transport endpoints, and available tools. This allows AI agents to discover and connect to your MCP server.

Why is this important?

Without an MCP Server Card, AI agents cannot discover that your site offers MCP tools. MCP is becoming the standard protocol for AI agent integrations, and discoverability is critical for adoption.

How to fix

Serve an MCP Server Card at /.well-known/mcp/server-card.json with serverInfo (name, version), transport endpoint, and capabilities.

Examples

GET /.well-known/mcp/server-card.json

HTTP/1.1 404 Not Found

GET /.well-known/mcp/server-card.json

HTTP/1.1 200 OK
Content-Type: application/json

{"serverInfo": {"name": "My API", "version": "1.0"}, "transport": {"type": "sse", "url": "/mcp"}, "capabilities": {"tools": true}}

Agent fix snippet

Copy this snippet and paste it into your AI coding agent to fix this issue automatically.

Serve /.well-known/mcp/server-card.json:

{
  "serverInfo": {"name": "Your Service", "version": "1.0"},
  "transport": {"type": "sse", "url": "/mcp"},
  "capabilities": {"tools": true, "resources": true}
}