When apps ask to have access to your contacts, do they just see the names, or do they see EVERY single detail you have saved?

When apps ask to have access to your contacts, do they just see the names, or do they see EVERY single detail you have saved?

(if so, that seems like a major privacy/security issue!)

With the focus on privacy, and transparency in sharing things with apps, I am surprised that we as users don't have more control over these type of details! (unless I am missing something)

When apps ask to share contacts, it is one thing to get the names, it is an entirely different thing to get all their phone numbers, relationships, addresses, notes, etc. etc.

Same thing applies when "sharing" a contact via iMessage.

Can we have a default 'limited' subset of information that is shared when sharing a specific contact? It seems there is 'some' control through macOS contacts, but it is severely limited, and there is NOTHING on iOS.