Invalid JSON RPC requests do not respond with an error

I noticed that this request:

{"jsonrpc": "2.0", "id": 1, "method": "tools/lit", "params": {}}

... returns an error response (code -32601) as expected but this:

{"jsonrpc": "2.0", "id": 1, "method_": "tools/list", "params": {}}

... returns nothing. I would expect that a missing method property or an unknown root property like methodX would throw and error. The JSON-RPC 2.0 spec says the server should return:

• -32600 "Invalid Request" for malformed JSON-RPC (missing required fields like method)
• -32602 "Invalid params" for bad parameters

I think the SDK should handle these but I'm not even able to write validation logic in my application code because an invalid RPC request never reaches my handler.

Claude tells me I can do something like this:

class ValidatingStdioTransport extends StdioServerTransport {
  // Override message handling to add validation
}

.. but I don't love that.

If a maintainer agrees that this validation should be in the SDK, I'd be more than happy to write a PR! Thank you for all your work on this!

Start by tracing StdioServerTransport's message-handling entry point and how requests are dispatched before reaching application handlers. Reproduce the missing-method and unknown-root-property examples, then verify that malformed JSON-RPC requests produce the specified -32600 or -32602 errors instead of no response.