No, it is not visible to everyone in a way that just pops up on random phones. It is meant to be tracked through your Samsung account and SmartThings Find, and Samsung says a tag can only be tracked and accessed by one device and/or account at a time.

A nearby Galaxy phone can help locate it through Samsung’s network, but that happens privately and anonymously; the other person does not get a normal “popup” showing your tag details. The other phone must also be opted into SmartThings Find and logged into a Samsung account to take part.

If someone is nearby and does not own it, Samsung also provides unknown tag detection/alerts so you can be notified if an unknown tag is moving with you.