This is something I've been having to slowly coach my players about, in Dungeon World.
Don't tell me you intend to make a roll. Describe what you're doing. Give me actions, thoughts, feelings. If those actions, thoughts, or feelings necessitate a roll, I'll tell you. Otherwise, I am happy to just give you answers.
It's that last bit that I think has done the most good to encourage people to pause on rolling. Well, that and the fact that a bad Discern Realities roll means the party will learn an unwelcome truth! (I never, ever speak falsely about Discern Realities rolls--I may sometimes give incomplete information, without specifically saying so, if the PC doesn't have any way to observe a particular piece of info, but I don't ever state things that are false.)
Since the players know they can learn a lot just by asking about stuff, they feel like they should ask around, show how they're delving into things, and then when their actions trigger a roll, they can make it at that time.