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.