the creator of this game made the tool having durability instead of craft a large quantity of tools, it means if the gem cutter has 5 durability, it means it crafts 5 gem cutter using same material before
and probably the creator want to make watering can profitable ( 2 plastic pellet for 4 watering can use equals 6 = 64 ) so it's little overpowered in early game but no if in late game