RenderDigimania has a good article about the “10 Things No Animator Wants to Hear”
“I don’t have any concept art or storyboards yet, but a story outline will do, right?”
No, it won’t. You wouldn’t ask a voice actor to do the gig without a script, so why ask somebody whose job it is to bring the images to life to do so without any bloody reference materials? We will just end up blindly firing out ideas, only to watch each one shot down, as we slowly and painfully try to find out what the hell you were actually looking for in the first place. Animators can do many things, but mind-reading isn’t one of them.
You can read the full article here.