If you don't know the mint, npub or any other entity really, either directly or indirectly (social graph), we have to assume it's not trustworthy.

This will become more and more true as Nostr grows

nostr:note1m7kskfyz4s9uwrar4swrxyy7wg6d0ufm2gyzeyklzs2dj48kn8mq9djfs5