Writing Supplement Format

One of the universities I’m applying to has two writing supplements that are required for the application. They’re each essays, and I have to type them as a word document then upload them to the common app. Is there any specific format I need to follow when I type my essays up? I have them in 12 point Arial font, double spaced. I didn’t put anything else on the page like my name or the prompt. Is this all that’s necessary? Any changes I should make?