Don't really have the problem with scissors. I have one pair of Ginghers that have been stuffed in a drawer ever since Fiskars put out the spring loaded scissors. Normal scissors just slip over my knuckles as I use them and it's uncomfortable. Most of the "normal" type scissors have colored plastic handles, and I don't care what he grabs as long as he puts them back. Same for my tool box. Put it back! Don't haul it out to your tool bench and leave it there!
What will infuriate me is if he takes marking tools or measuring tools. Taking my electrical clippers is a no-no.