"Is there anything cheaper?" — the agent names the cheaper plan and changes nothing; the customer picks Basic → one change.
“Is there anything cheaper than my current plan?”
“Yes, the Basic plan please.”
A multi-turn conversation: 2 customer messages, sent one after the other.
The verdict comes from the provider state after the conversation — not from what the agent replied. All of these must hold:
No faults are injected: the provider behaves. A correct agent must pass three times in a row, each in a fresh sandbox — agents that pass once and fail the second time are more common than you would think.