MCP Server Audit

mcp-server · v1.1.0 · paid

Evaluates MCP server implementations — tool definitions, transport protocol compliance, error handling, security boundaries, and capability negotiation.

Tool Definitions

tool-definitions · weight 0.3

Tools have JSON Schema inputSchema with types, required fields, and descriptions
ab-001825
critical
Tool names follow verb_noun or verb-noun convention with no collisions
ab-001826
high
Each tool has a description covering what it does, when to use it, and side effects
ab-001827
high
Resources use valid URI templates with mimeType set
ab-001828
high
Prompts have names, descriptions, and argument schemas
ab-001829
medium
Tools return proper content types (text, image, resource)
ab-001830
low
Tool annotations (readOnlyHint, destructiveHint, openWorldHint) are set
ab-001831
low
README shows how to connect to the server
ab-001832
info

Transport & Protocol

transport-protocol · weight 0.25

JSON-RPC 2.0 message format is correct
ab-001833
critical
Stdio transport reads stdin, writes stdout, no console.log pollution
ab-001834
critical
SSE or Streamable HTTP transport implemented correctly if offered
ab-001835
medium
Implements initialize method and returns capabilities
ab-001836
critical
Declares protocolVersion and handles version mismatch
ab-001837
high
Handles notifications without sending a response
ab-001838
low
Responds to ping requests
ab-001839
low

Error Handling & Resilience

error-resilience · weight 0.25

JSON-RPC error codes are used correctly
ab-001840
high
Tool handlers catch errors and return isError: true
ab-001841
high
Unknown methods return -32601 Method not found
ab-001842
high
Invalid JSON and malformed parameters return InvalidParams
ab-001843
high
Long-running tools have timeouts
ab-001844
medium
SIGINT and SIGTERM handled for graceful shutdown
ab-001845
medium

Security & Capabilities

security-capabilities · weight 0.2

Capabilities object accurately matches implementation
ab-001846
high
Tool arguments are validated against inputSchema before execution
ab-001847
critical
Tool responses do not echo secrets or credentials
ab-001848
high
File system operations are restricted to a declared scope
ab-001849
high
Expensive operations have resource limits
ab-001850
medium
Uses notifications/message for logging, not console.log
ab-001851
low