Check an MCP tool definition for required fields and common schema or annotation mistakes.
The checker reviews tool names, descriptions, input schemas, output schemas and annotations. For the current MCP specification, tool input schemas use JSON Schema and retain an object-root requirement.
Validate MCP tool names, descriptions, inputSchema, outputSchema and annotations.
Use MCP Tool Definition Validator as a focused pre-flight utility while building, reviewing or debugging an MCP integration. Paste the relevant configuration, protocol message, metadata, schema or value into the tool and review the returned findings before the same data reaches a production client or server.
This validator is useful before configuration is committed, shared with another client or moved into production. Structural validation catches many integration problems early, but runtime behavior should still be tested with the exact client and server implementation you use.
A clean result means the input passed the rules implemented by this utility. It does not guarantee application security, protocol interoperability or correct business behavior. Test important integrations against the exact MCP client, SDK, gateway and server versions used in your deployment.