I'm building out a Vapi <> Jobber integration for my app, but the custom tool call just isn't working! Even though Vapi is definitely getting the right response back: The Vapi dashboard confirms it's receiving this response from our server: { "results": [ { "tool_call_id": "call_KGXpFhrcvNyye0SqJ55A83R0", "result": "2025-05-10 is FULLY BOOKED. There are existing appointments blocking the entire business day (6:00 AM to 9:00 PM)." } ] } And the agent has been told, in its prompt, that "To check availability: When a customer asks about available times, use the check_availability tool When you receive a result from the check_availability tool, use that information to inform the user about the requested dates' availability." And yet in the actual conversations the agent isn't able to do this! Why might this be?

The issue likely stems from the assistant’s prompt or config not properly instructing it to use the tool’s result, ensure the prompt clearly tells the agent how to interpret and respond using the check_availability output.