ItemsAdder has a custom durability system that you can decide to use or not
If you want to set a custom durability for a specific tool you can! For example:
unbreakable: false #it's the Minecraft vanilla attribute
As you can see there are two special properties max_custom_durability, custom_durability and disappear_when_broken.
As you can see there is an indicator of the custom durability
It's precise as vanilla