The smallest voice-agent test I like: make it ask the missing question

I was testing a phone agent with a deliberately silly task: pretend you are ordering me a cheese pizza. The useful moment was not the voice. It was the follow-up question. The agent asked for the delivery address. I said, "use the address on file," mostly to see if it would just nod and continue. It did not. It pushed back and asked me to spell out the address so it could make sure the order was right. That is now one of my favorite tiny voice-agent tests. Give the agent an underspecified real-world instruction: - use the address on file - book my usual time - call them back later - send it to the manager - charge the card we used last time Then watch whether it asks for the missing source-of-truth detail before making the promise. A voice agent can sound smooth and still be dangerous if it politely commits to a thing it never verified. The quality of the follow-up question is often the quality of the agent. What is the smallest "do not assume this" test you use for voice agents?