The essay is intended to be a review of an article.  It should begin with full bibliographical information (This is in place of a title) and then address the following points:

What does the researcher want to find out?
How is the researcher investigating this? What sources are used?  Are they adequate to the task?
What does the research contribute to our knowledge of the field?
How does it compare with what you learned in class and textbook reading?  (What did you learn that was new?)
Who is the intended audience (an academic audience with background knowledge or a general audience with little knowledge of the topic, etc)?
Is the writing clear? Does it use direct, straightforward, and unambiguous words and phrases?