Here is Michael Barry’s general list of concerns for grading essays

An excellent essay will demonstrate:

Unity

• The thesis statement governs the essay
• The topic sentences govern the paragraphs (not merely as titles, but with some “predication”)

Specificity

Complexity

• The essay describes the way a source essay unfolds, and clarifies difficult passages
• It demonstrates sensitivity to audience
• It anticipates audience objections
• It departs from a five-paragraph formula
• It resists cliché
• It “notices” well, observes keenly
• It sees how things could be otherwise (it is imaginative)
• It makes use of complex sentence structures

Clarity, Precision, Conciseness

Another criterion would be “Does the essay address the assignment?” Under the heading “complexity,” my standards will be different depending on whether or not the assignment is research-based. There is no magic algorithm for applying these criteria to an essay. You might ask: which item on this list is most important? The conventional wisdom is that clarity is more important than all other considerations, for if it is truly absent, readers will not be able to evaluate the essay’s unity or complexity. But most college writers have achieved a minimum level of clarity such that other matters can be evaluated, so I hesitate to say that clarity is the fundamental criterion. By itself, clarity does not earn a student an “A.” You may notice, as well, that sometimes “specificity” pulls against “unity.” Highly specific examples have a centrifugal force that can pull them away from an essay’s core. But without examples, abstract assertions will not be memorable; hence the importance of specificity.

Here are a few comments that I make on many essays:

When you summarize a nonfiction reading, commit yourself. You’ve been trained to say nothing in 500 words, and I’m sure you can do it. But that’s not good writing. In the spirit of good writing that takes risks, look at the following:

Don’t say “The essay by Jacoby talks about pornography.” Anyone can say that who hasn’t read the Jacoby essay. Say “The essay by Jacoby says that pornography must be protected by the first amendment.” See the difference? “Says that,” not “talks about.”

In writing an early paragraph, don’t say “Gandhi explains what he means by nonviolence.” The “what” in that sentence is still a question word, waiting to be addressed. Answer it. Say, instead: “Gandhi explains that nonviolence is a form of ‘truth force,’ a full-time life project.”

[Especially for essays about poetry] When you quote a source, your quotation must function within a grammatically complete sentence. A few extra ellipses dots will not help you. All sentences in your essay should be complete sentences. Your own sentences are usually no problem in this respect. Full-sentence quotations, by definition, are also no problem in this respect. But if you have a composite sentence (partly your words, partly quoted words), it too must conform to grammatical rules. You can’t say Rilke says in line 12 “behind the bars, no world.” You have to make the seam unhearable between your words and Rilke’s. Say Rilke says that the panther appears to see no world “behind the bars.”

Essays in literature classes: The essay assignments in a literature class may differ from essays assigned in other disciplines in that they tend to ask for analysis. When you write about literature, get beyond plot summary, and address one or more of the questions that I have included in questions to ask of literary works. Look at the individual assignments. They will give some very specific advice, about matters such as leading a reader to a relevant quoted passage by means of plot summary. The following qualities are frequently demonstrated in excellent literary analysis essays:

• They are able to imagine how a work might have been different; this exercise helps writers to say why the author chose to do it the way he or she did it.
• They do not leave obvious counter-interpretations untended.
• They will address some of the complexities of the world created by and in the work of art; this may mean discussing irony, and it usually means including the end of the work of literature in one’s analysis (and this discussion of the end need not appear only at the end of the student’s essay).
• In all but the most experimental art forms, a unified student essay will make the work of literature in question seem like more of a unified whole too.