The noun tool has 4 senses (first 2 from tagged texts)
1. (15) tool -- (an implement used in the practice of a vocation)
2. (5) instrument, tool -- (the means whereby some act is accomplished; "my greed was the instrument of my destruction"; "science has given us new tools to fight disease")
3. creature, tool, puppet -- (a person who is controlled by others and is used to perform unpleasant or dishonest tasks for someone else)