I've just started playing, so I don't know if this is a bug, but I tried to get my bots to collect a tool if their hands are empty.
Ideally, collect a tool and use it until it breaks, then go collect another.
They were empty handed, as was my character.
I'm going to try again once I've got my level sorted :-D
for item movement scripts, have them pick things up until full, then deposit until empty. for things with tools, have them go until empty then go do whatever they do to get another tool. i just make mine make their own tools.