Should I get a coating on my child's molars?

I am a 10-year-old elementary school boy, and my school designates a hospital for annual dental checkups. When I go to this hospital, the doctor is not very kind and doesn't give detailed consultations, so I have the nurse tell me the results. They sit me down, spray something like disinfectant once, and then quickly look over my teeth and finish. Also, both last year and this year, the nurse told me the results. I don't have cavities, but they said that cavities can easily form on my permanent teeth, so I should get a coating. Since it's a hospital designated by my school, I had no choice but to go, but I feel like they are very indifferent, and I don't really want to get the coating there either. But I'm curious—does getting this coating really help prevent cavities? Some people say it's unnecessary, so I'm conflicted.