Unless the descriptions are absolutely crucial to the story, for example, a hat is red and the red color plays an important piece in the ending or something or the story will not make any sense without art notes (such as the words say the characters are sad, but in fact, the characters are happy), do NOT include art notes.
Even for the WIP award, art notes should only be included if absolutely crucial to the story line, not just because you envision the characters or setting look a certain way.
I hope this helps.