A Toa tool was a weapon (or multiple weapons) carried by a Toa used to focus and channel his or her elemental power.
A Toa tool did not need to be specially made to be able to focus its user's elemental power.1 A Toa could channel his power through any object.2
Some tools, like those of the Toa Nuva and Toa Metru, had dual-function abilities. For example, Tahu Nuva's magma swords, in addition to being used as conventional swords, could be attached together to form a lava surfboard.
Some tools not only channeled a Toa's power, but increased it in some way or granted additional abilities, as with the lava spear, cyclone spear, and power lance.