First find out what works to make him listen to you. Those video games that he can not find will drive him crazy also.
Her child her problem only works until it cost you money. Lock that box , it only took my dad 20 years to figure that out.
Yes buy him some tools and make sure he puts them back also. Make a spot for each tool so that he knows if they are missing.
Do not worry about making a mistake and if you do tell him you are sorry. He might pickup on that .