Focus on this idea is sharp throughout. There are no counterproductive digressions or tangents. The thesis is substantial and appropriately restricted. The essay provides a thorough and well-supported discussion of its thesis. There are enough points to advance the discussion, and each point is well developed.
Evidence is given where appropriate, and, when offered, it is detailed and specific.
The student is clearly using the writing as a tool to probe and comprehend the subject. The essay has a logical or otherwise systematic structure. There is a beginning, middle, and end. These parts are in proper proportion to each other. The essay's points and subpoints are arranged according to some plan.