Waila Harvestability Mod is a client-side add-on for Waila that contains documents involving in the harvestability you are looking at. By default, it express whether you can recently collect the block or not, the essential harvest level of the block, and the tool type that is effective against the block. Moreover, Waila modules configuration screen consists of various configuration options to tweak it to display exactly what you want it to.
Read more: Harvest Mod
While holding an Iron Pickaxe (with default settings):
Silk Touchability and Shearability:
Waila configuration screen: