Action Step: Check your assistant's hook configuration to ensure all referenced tools are correctly set up. For example, a valid hook should look like this:

json
{
  "hooks": [
    {
      "on": "call.ending",
      "do": [
        {
          "type": "tool",
          "tool": {
            "type": "transferCall",
            "destinations": [
              { "type": "number", "number": "+1234567890" }
            ]
          }
        }
      ]
    }
  ]
}

Review your configuration in the dashboard and verify that each tool used in your hooks exists and is accessible. For more details, see the [Assistant hooks documentation](https://docs.vapi.ai/assistants/assistant-hooks). Source: - [Assistant hooks](https://docs.vapi.ai/assistants/assistant-hooks)

Please share the Call ID along with any error message you are receiving. This will help us investigate the issue more effectively.