The Elements of Writing Prompts

In terms of the elements of a prompt, there is—and isn’t—a lot going on here, all at the same time. If we apply the steps of the assignment prompt decoder exercise to this prompt, we see that the 

• purpose isn't really stated, though we can imagine that the goals include making sure students keep up with readings, giving students the chance to apply lectures and/our class discussions to their own arguments, putting primary and secondary sources into conversation with one another, and/or highlighting differences between novels and documentary films
• genre is somewhat stated—it's an essay—but it's unclear whether it's supposed to be an argument, and, if so, what kind of argument. Is it a "lens/test a theory" kind of argument using the secondary readings, or would it become a comparative analysis of several primary sources if the student goes beyond "at least one" novel or film? 
• evidence and analysis are also somewhat addressed, at least in so far as we have a sense of the parameters of evidence students should be working with. But is it better to use more than one novel or film? And how many secondary readings does "other" mean? And what kind of analysis would result in the student working with more/fewer sources? And what does it mean to "use" a novel or documentary film along with secondary readings? 
• audience isn't stated, though presumably it's the students' TFs? 
• style isn't addressed beyond "focused" and "clear" (which are themselves on the vague side of things)  
• specific guidelines are relatively concrete (students know the length and when to submit things)
• process isn't addressed at all. 

Based solely on what's in this prompt, the implied rubric would mean giving students feedback on:

• how clear and focused their writing is
• that what they have written is "an essay" 
• whether it is 4–6 pages long 
• whether it uses at least one novel or documentary film from the course along with other assigned secondary readings, and
• whether it was submitted by 6pm on November 4. 

As far as rubrics go, that's a difficult feedback scenario for students and teachers alike, because the first two bullets of the rubric are awfully hard to apply objectively—based on the prompt—and the last three bullets are merely objective. What we can see here is this: if meaningful feedback is a means for talking to students about their learning, we need a rubric that helps us to do so transparently and consistently; and for the rubric to serve as a common touchstone for everyone involved in the assignment, prompts need to err on the more explicit side of things with as many of their elements as possible.