If they get in the shop, which would require a quickie saw or some hardcore pry tools, then they can get to whatever they want. If they get in my truck box, same deal. Thieves with the gall to rob a shop don’t take the first thing they see and leave, in my experience. It’s also pretty nice to have somebody there for something like twelve to sixteen hours per day six days a week, at least during the busy season.
If I’m at the shop, the blue heeler/border collie mutt can be one mean bastard to strangers, he’s fifty pounds of spitfire fur missile that goes most places I do and seems to judge intention better than I can. I don’t keep many tools at home, but he’s the same way there.