The person given a key has received access whose limits still deserve understanding.

Being trusted with a key is not the same as being told what it means. It answers whether you can get in and leaves open when, how often, and what you may do once you are inside. People rarely spell out those edges, partly because saying them aloud can feel like withdrawing the trust. So whoever holds it guesses, and either uses it too freely or hardly at all.

If you have given somebody access, say plainly what it is for and when it applies. And if you hold a key you are unsure about, one direct question makes it usable instead of leaving it in a drawer.