A Springboard for an animation writer consists of nailing down the idea to one or two clear and catchy sentences. Basically it’s the TV GUIDE version of the story.

An example of this would be:

Bob is angry that Dave got the promotion so he sets out to get him fired. Meanwhile what he doesn’t know is Dave is planning a surprise birthday party for him!

Usually it’s short simple and sweet. Most writers are asked to submit a number of them. one of which is picked and then fleshed out.