Final answer:
Tool marks can be classified based on the size and shape of the impression, physical features like nicks and chips, material residue left on a tool, and ridges or striations on the surface.
Step-by-step explanation:
Tool marks can be classified two ways: features to analyze the size and shape of the impression, physical features such as nicks and chips, material residue left on a tool, and ridges or striations on the surface.