You should still be able to ask what the job entails in a general sense. (Like clerical, data analytics, design, etc...) It's usually where the give their spiel such as, "You will be helping to design and roll out a new system that helps focus our resources on what's important; the people."

They may be talking out of their ass, but at least you could glean at a very high level what you'll be doing. (Otherwise a revolving door of dissatisfied hirees could open up)