I will answer my own questions here. the core issue is that I put the wrong id as the "toolCallId". There is a field "body.message.call.id" which I thought should be the call id. but obviously it is wrong. The right field is "body.message.toolCalls[0].id" Also if you want to check the response of the tool call you can see the log and response data "Observe -> Webhook Logs" hope it helps for whoever runs into the same issue