What the description field is actually for
Google Business Profile gives you 750 characters to say what the business does and where. It is not a ranking lever on its own, but it is what a person reads when they are choosing between you and the shop two streets away, and it is often the only prose about your business they will see.
The first line matters most, because it is what shows before the "more" link. Say what you do and where you do it there.