Man, that’s a tough one, because it sounds like this was more of a brain fart thing than a maybe a sign on the woodshop door saying something to the effect of “Packing up? Remember to check your pockets/toolkit for VHS common tools so that they don’t go home with you.”
Another good measure could be to engrave VHS common tools with “VHS - vanhack.ca NO PAWN” Did this at CoLab when I was there and I think it helped to stop the tools from walking, both from absent-mindedness and from malice.