You consent to a scope of work. If you want line item control over exactly how the work gets done, what tools the workman gets to bring, what creature comforts he is and isn’t allowed on the jobsite, that’s something you can negotiate.

Like if you’re Amish or under some weird historic preservation regime or working near a delicate billion-dollar scientific instrument. Perhaps you really need carpentry done with hand tools. You can find a contractor who wants to do that. You don’t hire a normal firm and then get mad that they failed to seek consent before plugging in their table saw.