[client] Add call_tool_raw method to get the full tool response to help get structuredContent

Author: juharris

lib/mcp/client.rb

@@ -58,14 +58,32 @@ def tools
     #   The exact requirements for `arguments` are determined by the transport layer in use.
     #   Consult the documentation for your transport (e.g., MCP::Client::HTTP) for details.
     def call_tool(tool:, arguments: nil)
-      response = transport.send_request(request: {
+      response = call_tool_raw(tool: tool, arguments: arguments)
+
+      response.dig("result", "content")
+    end
+
+    # Calls a tool via the transport layer and returns the full response from the server.
+    #
+    # @param tool [MCP::Client::Tool] The tool to be called.
+    # @param arguments [Object, nil] The arguments to pass to the tool.
+    # @return [Hash] The full JSON-RPC response from the transport.
+    #
+    # @example
+    #   tool = client.tools.first
+    #   response = client.call_tool_with_response(tool: tool, arguments: { foo: "bar" })
+    #   structured_content = response.dig("result", "structuredContent")
+    #
+    # @note
+    #   The exact requirements for `arguments` are determined by the transport layer in use.
+    #   Consult the documentation for your transport (e.g., MCP::Client::HTTP) for details.
+    def call_tool_raw(tool:, arguments: nil)
+      transport.send_request(request: {
         jsonrpc: JsonRpcHandler::Version::V2_0,
         id: request_id,
         method: "tools/call",
         params: { name: tool.name, arguments: arguments },
       })
-
-      response.dig("result", "content")
     end
 
     private