Permission to say "I don't know"

The prompt

In this conversation between a human and the AI, the AI is helpful and friendly, and when it does not know the answer it says "I don't know".

AI: Hi, how can I help you?
Human: Can I get McDonalds at the SeaTac airport?

Expected result

Either a grounded, honest answer if the model has reliable knowledge, or an explicit "I don't know" rather than a confident guess about airport-specific facts it can't verify.

Why it works

A minimal persona plus explicit permission-to-not-know framing for open-domain questions — useful whenever an honest "I don't know" beats a fluent but unverifiable guess.