Hey, I saw many posts on this issue, tried to verify all possible issues, stiil dont understand. I have 3 tools in the assistant and all of them works fine-just one of them returns a correct response from Make and assistant does NOT read it until he is being asked, then it is actually correct. any help? https://cdn.discordapp.com/attachments/1365375232449319043/1365375232575017011/Screenshot_2025-04-25_at_20.12.23.png?ex=680d1446&is=680bc2c6&hm=5dcb088f00d241d95fb24abbd120fdb79d856bce86f68e2089a56c0344deff98&

Check your response format - ensure the

content-type

header is set to

application/json

and verify your JSON structure matches exactly what Vapi expects:

json
{
  "results": [
    {
      "toolCallId": "call_aKGUbHhYykjRtJBYBNJ",
      "result": "Available slots at 2:00 pm, 3:00 pm, 3:30 pm, 4:00 pm, 4:30 pm."
    }
  ]
}

Make sure the

result

field is a single-line string without line breaks. Sources: - [Discord discussion about Vapi response issues](https://discord.com/channels/1211482211119796234/1334658296291921920) - [Discord thread about toolCallId matching](https://discord.com/channels/1211482211119796234/1325000684231196775) - [Discord post about content-type headers](https://discord.com/channels/1211482211119796234/1335771378435231797)

Can you send me the latest call_id where you had this issue?

call_1Ag7aWeBPJIpl1IHnGh9JPOi

Try switching your tool from asynchronous to synchronous mode in your Vapi dashboard: 1. Go to your Vapi dashboard 2. Navigate to the problematic tool configuration 3. Find the tool settings and change from

async

to

synchronous

json
// Make sure your response format is exactly:
{
  "results": [
    {
      "toolCallId": "call_1Ag7aWeBPJIpl1IHnGh9JPOi",
      "result": "Your single-line result string here"
    }
  ]
}

Source: - [Discord discussion about synchronous vs async tools](https://discord.com/channels/1211482211119796234/1342315282198298729)

To help track down this issue, could you share: - The call ID This would really help us figure out what went wrong!

Oh right sorry. call id:d56fc6dd-ce6a-4812-ae30-3240179db2f5