It is not used to ask if something is allowed, as in “Is it okay for us to wait here?”.
It might be used in answering such a question though;
- Est-ce que ça va si on attend ici ?
one might then answer as follows;
- D’accord, vous pouvez attendre ici.
But then, implicitly the person answering is telling you that this possibility is conceived rather on the basis of their personal judgement and/or authority over the place.
If you use « d’accord » to ask the question instead, then you are asking specifically the given person whether they give their permission, you are not asking whether, according to habits, customs, rules etc. you might do that, and you do the asking as follows;
- Êtes-vous d’accord pour que nous restions ici ?
Is it okay with you if we wait here?
There are variants;
Est-ce que vous êtes d’accord pour que nous restions ici ? still the standard register
C’est d’accord si on reste ici ? somewhat informal