Funny enough I already wrote an answer to you 3 months ago about that^^ (And linked it twice the last month I think.)
This and the following posts from me should be pretty much the whole idea.
TL:DR Find stones on the floor. Bash them together to make tool heads. Take sticks from leave blocks. Make tools directly from stones instead of wonky wooden ones.
@AndyD Well visually and game wise you’d have an empty hand yea.
The pointer would be on both radials on the axe in this example but you’d only have it displayed once and you can only use it once.
Maybe the hand you had equipped it first is the one showing the tool. And the default for switching both at the same time would be your main hand (if that’s going to be a thing, if not maybe just the right hand?)