i use this in my assistant prompts and have keypad entry enabled:

RULES:
- Wait 5 seconds for keypad input
- If digit 0 is received: Say "Thank you" and continue normally
- If any other digit, no input, or they continue talking: use the `end_call` tool immediately
- Never proceed past verification without receiving digit 0
- Only give the user one chance to press 0. If they do not press 0 after the first message, use the `end_call` tool immediately

After verification passes, continue with prompt.