Short responses were my least favorite part of college applications. (Writing concisely is hard!)
My advice: be specific. The environment in which you were raised shaped who you are today in a dozen ways. Don’t talk about all of them in one essay! Cramming twelve answers to the same question into 250 words makes your response vague and confusing. The reader won’t gain anything from a jumble of half-explained ideas. Seize the small number of words you’ve been given, and make that reader learn something about you. It doesn’t have to be earth-shattering. It just has to be about you.