Short answers, pulled from the story.
A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help accomplish a particular task. In its proto-typical sense it refers to a solid hand-operated non-biological object with a single broad purpose, unlike machines or computers.
Stone artifacts date back to about 2.5 million years ago, and finds of actual tools date back at least 2.6 million years in Ethiopia. A 2010 study suggests Australopithecus afarensis carved animal carcasses with stone implements around 3.4 million years ago.
Benjamin Beck published a widely used definition of tool use in 1981. It describes the external employment of an unattached or manipulable attached environmental object to alter the form, position, or condition of another object, organism, or the user itself.
The six classic simple machines are the wheel and axle, lever, pulley, inclined plane, wedge, and screw. Several were invented in Mesopotamia, with the wheel and axle first appearing in the potter's wheel in what is now Iraq during the 5th millennium BC.
Observation has confirmed tool use in monkeys, apes, elephants, several birds, and sea otters, among others. New Caledonian crows are among the only animals that create their own tools, while humans are considered the only species that uses tools to make other tools.
Machine tools occasioned a surge in producing new tools during the Industrial Revolution by enabling the economical production of interchangeable parts. Their inherent precision allowed better working machinery, interchangeability of parts, and standardization of threaded fasteners such as machine screws, bolts, and nuts.