You should have multiple sources. All your information must be carefully collected and attributed. You may not include any unattributed opinion. You must try to represent various perspectives, especially when dealing with a controversial subject. Write clear, short sentences using strong, active verbs.
Conciseness is a virtue.
The tone must suit the content. You must follow stylebook rules. These points, added up, form your preliminary grade. After that, an unlimited number of points can be deducted for grammar errors and factual errors. Check the class web site for the gradesheets for assignments.