bug: Invalid method parameters while calling tool

[piyushgithub15]

Description

A clear and concise description of the bug, including what happened and what you expected to happen.

Code Sample

       	sseTransport, err := transport.NewStreamableHTTP(
		"https://mcp.stripe.com",
		transport.WithHTTPHeaders(headers),
	)
	if err != nil {
		log.Fatalf("error")
	}

	mcpClient := client.NewClient(sseTransport)
	defer func() {
		log.Println("Closing MCP client...")
		mcpClient.Close()
		log.Println("MCP client closed.")
	}()

	callToolReq := mcp.CallToolRequest{}

	callToolReq.Params.Name = "get_stripe_account_info"
	// Always give Arguments a non-nil empty map so the JSON will include `"arguments": {}`
	callToolReq.Params.Arguments = nil
	// DEBUG: inspect exactly what you’re about to send
	buf, _ := json.MarshalIndent(callToolReq, "", "  ")
	fmt.Println("Outgoing payload:\n", string(buf))

	results, err := mcpClient.CallTool(ctx, callToolReq)
	if err != nil {
		// 3) Use a format verb so the error actually prints:
		log.Fatalf("CallTool failed: %v", err)
	}
	log.Printf("tool result: %+v", results)

Logs or Error Messages

2025/05/26 19:24:11 CallTool failed: Invalid method parameters: T.cast: Expected type T::Hash[T.any(String, Symbol), T.anything], got type NilClass
Caller: /deploy/pay-server/current/lib/model_context_protocol/server/synchronous_http_server.rb:213
exit status 1

Environment

• Go version : go 1.23.0
• mcp-go version : v0.30.0
• OS : Mac

Additional Context

If any tool has no arguement then we faces this issue.

Possible Solution

In the case of no arguments required dummy arguments works fine.