There are several different tools in the game, and most can be upgraded.
Primitive Axe
Fine Axe
Great Axe
Master Axe
Runic Axe
Build Tool
Bugnet
Great Bugnet
Camera
Primitive Rod
Great Rod
Master Rod
Primitive Hoe
Fine Hoe
Great Hoe
Master Hoe
Primitive Pickaxe
Fine Pickaxe
Great Pickaxe
Master Pickaxe
Runic Pickaxe
Shovel
Fine Shovel
Great Shovel
Soul Sounder
Sickle
Silver Sickle
Golden Sickle
Watering Can
Silver Watering Can
Witch's Broom