If it is a higher up, someone I am actively working with, or someone I know well, then I take the "quick call". Otherwise, I push back and ask them to write out their question somehow.

This ends up a few outcomes, usually positive:

  - They give up (pretty common)
  - Writing it down helps them to answer the question themselves
  - I can directly answer with a response or link to the relevant docs
  - We have an actual agenda for the meeting they want to have