Honestly, I think most posters are overthinking this topic. These are mostly 13 year olds. Write whatever you want. The essay should first and foremost show that you can write grammatically and proofread. You are showing that you are strong writer and you will succeed in their classrooms without the need for remediation.
After that it is great if you can also do some of the following in your essay, but don’t stress:
- Be authentic and genuine to who you are and what you care about.
- Reveal your personality and real voice. But don’t mistake real voice for emoticons and teen-speak (like rofl or jk or lol). Don’t use slang or colloquial expressions or at least be judicious in their use. Also don’t fill it with thesaurus and dictionary words. You don’t want to sound pretentious.
- If you can make it moving or funny so that it stands out enough for readers to remember later, that is also great because chances are they will revisit your application again in a final round when they have 300 qualified applicants whom they love and only room for 100 new students. But moving doesn’t necessarily mean writing a sob story. It can be any genuine story that helps the admissions people get to know you, empathize with you, OR want to meet you/have you on their campus.
- Don’t overthink it but write with depth and complexity. If you can do, you should dig a little below the surface of what is obvious about you. This can be hard for a 13yo to do well though. If you can pull off a metaphor that is great but again don’t be pretentious. If you can’t do complexity well, just keep it simple.
- Don’t turn it into a list of accomplishments or bragging about yourself. Hopefully you have managed to put your accomplishments, activities, and prizes (if you have them) in the other parts of the application. The essay is not a resume or a chance to repeat what you have already written.
I really don’t think the admissions officers are assessing “what you can do for the school.” That type of stuff is already in other parts of the application as are your qualifications. However, they are assessing fit. Are you the type of kid who they’d enjoy having in their community? Are you the sort of kid who will thrive at their school? So if there is room to demonstrate that you actually know the particular school, you want to attend that specific school, and it is a particularly good fit for YOU (as opposed to you are blindly applying to the most prestigious names), you should show it. But you aren’t arguing a case about your fit. You are showing the fit by letting them see you through the essay.