The Show Durability 2 Mod gives you a HUD that shows the active tools durability right above the hunger bar. (can be turned off)
Also the durability of your armor will be displayed at the left or right side of your hot-bar (can be turned off, configurable).
The durability is displayed in color, similar like the color of the durability bar from vanilla. (configurable)
This mod is compatible with Tinkers Construct Items as of version 1.2.8.
Download: (in case the mod functionality is not working again: Curse-Link)
Or download it via my adf.ly link:
or the experimental version for 1.7.2 (with forge 10.12.0.991 or higher)
Here some Pictures: