Logical, clear order with original transitions. Completely clear, vivid, interesting prose. Less than two grammatical and mechanical errors per page. Strong opening, body, and conclusion. B level work Meets all basic requirements of papers.
Topic is good but perhaps unoriginal.
A few sentences don't relate to the thesis. Thesis is clear and arguable. Strong proof of thesis, but may not be vivid or totally compelling. Some missing or weak transitions, maybe one thing seems out of order. Between two and five grammatical and mechanical errors per page.