Most American TV animation is not animated here in the states, instead its sent to China, Korea or India and sometimes Canada. We do the preproduction, like the storyboards, the animatic, the designs and the background keys. We often do exposure sheets as well. Below are some director notes and draw overs on animation that I did for the second season of Woody Woodpecker shorts on Youtube. You can see all the Woody shorts here if you like.
Most times it was plussing the pose but in some cases to explain how to act the scene out better.