VoiceOver announces "Tab bar" or "Toolbar", the first time you select an element in one of these components. If you are implementing your custom versions of these, you can mirror this behaviour, as seen in previous tweets.

https://x.com/dadederk/status/1558045414082871298?s=20&t=LA95j22apvWsUqShqWGBzA

Two examples. The first one shows the Apple TV app. When VoiceOver's focus moves from outside the tab bar to one of the elements in the tab bar, it will prepend the accessibility label of the container view, in this case