I consider it my job to figure out the requirements. The fact that they aren't specified in detail allows me to do what I think is best rather than being bound by often arbitrary specifications.

I judge which decisions I make and which ones I bring up to my team/PO/whatever. Most of the time I just do what I think is best, some times I'll do something and then bring it up later like "I did this this way but if that doesn't work I can change it", typically for things that will be easy to change later. Some things I ask about before I do them because they won't be easy to change later.

I'll often take technical liberties with frontend designs, for example I'll use a html select rather than reinventing the drop-down just to be able to put rounded corners on the options. I'll style scrollbars using the very limited options css provides rather than reinvent scrollbars just to follow the design exactly. Most of the time nobody cares, we can always go back later and do these types of things if we really want a certain aesthetic.

I have never had the impression that my questions bother people, rather the opposite. I've had multiple designers say they appreciate the way I interact with them, I respect their work and their designs but I ask them if something looks like an oversight or I'm not exactly sure what their intention is. POs and such are always happy to answer simple questions, I make it easy for them: here's a decision we need to make, I want you to make it. Maybe I have a suggestion for what I would prefer and some reasons why I prefer that solution.

I don't expect them to think of everything and answer all my potential questions in advance, that's just unnecessary and difficult work.