Portable generator— permit for switch install in Virginia?

Hey all— first post. We just got a 10,000 watt generac generator to back up our panel box when the power goes out. Our house is on a well, and we really just want to power the well, refrigerator, and a few other things. We plan to wire the generator directly to our panel box with a transfer switch. The electrician who plans to do it says we don’t need a permit for the work since the generator is so small. Do we need a permit to work on the electrical panel? What happens if the electrician doesn’t pull a permit? We live in Virginia. Thanks!