It's a very straight forward mod with little needed documentation.

It adds (as of now) 4 new modifiers to Tinkers' Construct 2.0:

1. Auto-Repair (levelable like the old version; caps at Auto-Repair V)
2. Bonus Modifiers (level I, II and III), they work the same as the old bonus modifiers

Because of the nature of the new Tool Forge / Tool Station, I had to add new items to make working recipes for the bonus modifiers.

This is why there are now "Bonus Modifier" items added, as well as a moss ball. The bonus modifiers use (mostly) the same resources that the original Tinkers' tool station recipe did - but it's a normal crafting recipe that you then apply to the tool after crafting it.