I don't know if you've read the last message but i can tell you directly. As far as i know you could make the bot mine out the stone needed with a pickaxe (that it has to make or someone nedds to make for it) or it can simply use wooden axes. (If i'm wrong about the bots aren't yet able to do any of those sorry, I'm not quite that far into the game yet)
Bots are able to make their own tools. What they cannot do is switch a workbench to making another product. So you'll need a dedicated workbench for each required tool.
Teach the bot to
- pick up one plank from one storage
- add it to the workbench
- pick up one pole from another storage
- add that to the workbench too
- find the produced tool
Advantage over prefabricating tools: No overhead.
Personally I find it sensible to produce overhead only on base products like planks, poles, metal. And even there I now stop producing them when my storage is close to full. The result is a tidier map.