After having taught this class a number of times, I'm confident in assessing a grade that is commensurate with the departmental guidelines and the performance of current and past students. The challenge is to then communicate clearly how students might improve their performance if they wish to do so. I will continue to provide comments throughout the assignment, but in summary I will provide a breakdown rather than prose commentary.
In assessing work I consider four variables to be of greatest importance: engagement, understanding, writing, and scholarly support.
The grading rubric in the syllabus and its link to student evaluation guidelines has more detail. To see an examples of a good v. better writing, you can also see What Makes a Good Response?
The final grade is holistic and is informed by but not formally computed from the variables above; rather they are provided so you might most easily identify and improve upon earlier performance.