To get a toolsmith villager, you need to have a smithing table.
Smithing tables are made with four wooden planks and two iron ingots. The wooden planks can be made from any kind of wood.
When a smithing table is placed in a village, there is a chance that any villager who doesn’t already have a job will become a toolsmith.
The smithing table only has one function, other than providing a job to a villager. The smithing table can turn your diamond gear into netherite gear.
When you upgrade your gear using a smithing table, the gear retains all enchantments and any lost durability points.