What your pickaxe does
The pickaxe breaks eggs. The official description also names pickaxe upgrades as part of progression. A harder target is useful only when you can finish opening it and deliver the animal.
When an upgrade helps
Time the opening part of a familiar run, then compare it with the return. If breaking takes most of the attempt, inspect the next pickaxe offer and its current cost. If delivery fails, fix that before assuming a tool purchase solves it.
Prices and the rarest pickaxe
Video titles mention rare pickaxes, but the collected sources do not establish a complete, current shop table. Read the live price and power display; this guide does not invent a best-in-slot name or price.