tool has 11 distinct synonyms spread across 4 of its 8 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
the means whereby some act is accomplished
“my greed was the instrument of my destruction”
drive
“The convertible tooled down the street”
ride in a car with no particular goal and just for the pleasure of it
“We tooled down the street”
Synonyms, antonyms and the broader and narrower relations for tool come from Princeton University’s WordNet. Full sources and licences.