I have asked (and have been given) the guidelines ahead of time. It would be interesting for a scheduler to post their thoughts on here about that.
It seems lame that any MSC would want to hide the details from someone, only to have them take an assignment and then review and tell you "forget it" and then have to repost the shop again. But some MSC are over-protective of their clients and reports. Just like the MSC that won't name the business, but you can google the address and know who it is. They think they are fooling us by keeping the name hidden.
I have asked for basics (if not willing to share) like how many questions and how much narrative