The Elements of Writing Proficiency
Sentence level clarity: Sentences should establish a clear, precise relationship between the central idea of a paragraph and the supporting details that demonstrate the logic or reasonableness of the idea.
Arrange the words within each sentence grammatically. Abide by the rules of spelling and punctuation. The issue here is not that you must precisely follow rules; rather, it is that these rules helps us to communicate our meaning effectively and clearly to an audience. Your essay will be read and evaluated by criteria that values critical and analytical reading and writing. To communicate ideas effectively, you must do it in a way that your readers understand exactly what you intend to say.
Use appropriate diction. Avoid using clichés, which express "commonly" accepted understanding. Remember, you want to demonstrate you are able to critically understand a topic, and that you can think independently, rather than in a "commonly" accepted manner.