I structured the response as per Vapi's requirements, and it is returning the expected response in make.com, postman and on the vapi tool test page, however in live calls and chats no data is returned. The data is a JSON object with patient data. I made sure to include the tool call ID, and this is visible when testing in make.com. https://cdn.discordapp.com/attachments/1411040162615660715/1411040163458584658/Screenshot_2025-08-29_at_17.01.12.png?ex=68b3350e&is=68b1e38e&hm=7a5575a16f86d5df8706f1b49b0d24695aa553550e3734bb725bf68285930cc3&

Hi weronika, To address the "no result returned" issue for your tool during live calls and chats, consider these steps: 1. **HTTP Status Code**: Ensure your webhook returns an HTTP status of 200, even if there's an error in the response. 2. **Response Format**: Double-check that your JSON response format is correct. It should be:

json
   {
     "results": [
       {
         "toolCallId": "your_tool_call_id",
         "result": "Your single-line string response"
       }
     ]
   }

Avoid line breaks in the result field and ensure the toolCallId matches the request. 3. **Token Limits**: If data truncation might be an issue, consider increasing the token limit. Adjust the

maxTokens

in your tool configuration if necessary. 4. **Schema Validation**: Ensure that all required parameters are included in the tool schema and that schema validation is enabled with

"strict": true

. 5. **Call Logs**: Check your call logs for any schema validation errors, token truncation warnings, or HTTP errors that might provide additional insights. For further guidance, you can refer to the [Custom tools troubleshooting guide](https://docs.vapi.ai/tools/custom-tools-troubleshooting). If this doesn’t resolve the issue, please let us know and we’ll be happy to step in and assist further.

Point 2- my result is not a single line string response. It’s a full JSON object. Is that the problem?

Have you tried any of the troubleshooting steps?