Issue Description My voice bot was not functioning for the past 3–4 hours, and there were no relevant logs visible in Vapi to help identify the issue. While debugging the server logs, I found the following error:

Couldn't get tool for hook. toolId cae87f5e-5c77-4955-aa0e-941dda71599e does not exist.

I then reviewed the assistant configuration and history and noticed that this tool was not added to my assistant. However, I did not make any changes that would have removed it. Could you please investigate and confirm how this tool reference was introduced or why the assistant attempted to access a non-existent tool? Additionally, please let me know if there were any system-side changes or configuration updates that could have caused this issue.

Hey, Can you share your organization ID and the call ID where you encountered this issue so I can look into it further?

OrgID = 92e2c7f7-6041-4cc7-9ee7-c1c19b5f0ad0 CallIds = [019e84f0-452b-7888-bb19-a1afb2853f1e, 019e84f0-0bf9-7000-8504-f3e439cb69ab, 019e84ec-f53b-788e-bb28-0c8ed0a7fd7a, 019e84e8-c1ce-7aa5-820d-91ed72d1ff0e]

Hey Ahmer, I checked the logs for your org, and this appears to be caused by a stale hook level tool reference rather than the assistant randomly invoking a new tool. Your setup is also using a dynamic assistant endpoint on the phone number, so runtime config can be introduced there in addition to what appears in the assistant configuration. could you review and re save the hook related configuration returned by your dynamic assistant flow, and also check any number level hook settings, to make sure they no longer reference deleted tool IDs.

I reviewed the code, I didn't define any tool from my server's side and in the version history of assistant, addition of tool is not present as well.

Hey Ahmer, Could you remove and recreate the customer.speech.timeout end-call hook, then test another call? Please let me know if this resolves the issue. Regards, Priyanshu

I removed the tool, and the voice bot started working correctly again. However, could you please help me understand why this happened in the first place?

Glad to hear that your issue is resolved. This was a one off incident, and I will be investigating the cause. We will implement any fixes if needed. Let me know if you need help with anything else.