SMS tool not sending messages after assigning to agent
Hi VAPI team,
I’m using the SMS tool and have already assigned it to my agent, but it’s not sending out SMS messages. The tool executes but I keep getting an error instead of delivery.
Here’s the error I’m receiving:
{
"success": false,
"errorCode": "INVALID_PHONE_NUMBER",
"message": "Invalid recipient phone number format"
}
And here are my SMS tool details:
{
"id": "9bde4e90-4137-4b71-87ca-cd55ca953271",
"createdAt": "2025-09-03T13:22:06.685Z",
"updatedAt": "2025-09-03T20:49:51.413Z",
"type": "sms",
"function": {
"name": "send_text",
"description": "Send a pre-approved text message to the prospect. When a lead wants to book a showing, but prefers to self-schedule. Message: Thank you for your interest! You can book a private showing here: https://www.booking.com\n\n",
"parameters": {
"type": "object",
"properties": {},
"required": []
}
},
"messages": [
{
"type": "request-start",
"content": "I'll send you a text message right now with the appointment booking link.",
"blocking": false
},
{
"role": "assistant",
"type": "request-complete",
"content": "Perfect! I've sent you the text message with the appointment booking link. You should receive it shortly.",
"endCallAfterSpokenEnabled": false
}
],
"metadata": {
"from": "+18564925986"
},
"orgId": "e431800d-ac23-4af2-bb19-50f45b16351f"
}
Please help me to solve that
Thanks in advance!
I’m using the SMS tool and have already assigned it to my agent, but it’s not sending out SMS messages. The tool executes but I keep getting an error instead of delivery.
Here’s the error I’m receiving:
{
"success": false,
"errorCode": "INVALID_PHONE_NUMBER",
"message": "Invalid recipient phone number format"
}
And here are my SMS tool details:
{
"id": "9bde4e90-4137-4b71-87ca-cd55ca953271",
"createdAt": "2025-09-03T13:22:06.685Z",
"updatedAt": "2025-09-03T20:49:51.413Z",
"type": "sms",
"function": {
"name": "send_text",
"description": "Send a pre-approved text message to the prospect. When a lead wants to book a showing, but prefers to self-schedule. Message: Thank you for your interest! You can book a private showing here: https://www.booking.com\n\n",
"parameters": {
"type": "object",
"properties": {},
"required": []
}
},
"messages": [
{
"type": "request-start",
"content": "I'll send you a text message right now with the appointment booking link.",
"blocking": false
},
{
"role": "assistant",
"type": "request-complete",
"content": "Perfect! I've sent you the text message with the appointment booking link. You should receive it shortly.",
"endCallAfterSpokenEnabled": false
}
],
"metadata": {
"from": "+18564925986"
},
"orgId": "e431800d-ac23-4af2-bb19-50f45b16351f"
}
Please help me to solve that
Thanks in advance!
