Green’s Dictionary of Slang

tool n.1

1. as a lit. or fig. bodily organ (primarily the penis) [sense 1c from sense 1a on model of prick n. (3)].

(a) [mid-16C+] the penis.

(b) [late 17C] the vagina.

(c) [late 17C+] a stupid, useless, socially inept person .

2. in senses of that which is used [SE tool, an instrument of manual operation, ult. ON tol, to prepare or make].

(a) [late 17C–mid-19C] an unskilful workman; usu. as dull tool, poor tool.

(b) [19C] a whip.

(c) [mid-19C] (UK Und.) a small boy who is put through a window that is too small for the adult members of that gang to enter and who then opens the door to admit them.

(d) [mid-19C–1960s] (UK/US Und.) that member of the pickpocket team who does the actual stealing; the wire n.2

(e) [mid-19C+] (also toolie) a weapon, usu. a gun, knife or razor.

(f) [late 19C+] a burglar’s implement, spec. a jemmy.

(g) [1960s+] (US campus, also power tool) a very hard worker.

(h) [1990s+] (US drugs) a hypodermic syringe.

In compounds

toolbox (n.)

1. [19C+] the vagina.

2. [1990s+] (also toolshed) a group of idiots, or just a very extreme idiot.

tool chest (n.)

[19C] the vagina.

toolhead (n.) [-head sfx]

[1970s+] (US campus) a fool, an idiot.

tool house (n.)

[1960s] (Irish) a urinal.

toolman (n.) [sense 2e/2f + SE man]

1. [1940s+] a lock-picker; one who deals with alarms etc.

2. [1940s+] (US) a safe-breaker.

3. [2000s] a gun-carrying robber.

tool merchant (n.) [merchant n.]

(UK Und.) one who carries and uses a knife.

In phrases

have broken tools in one’s garage (v.)

[1970s] (US) to be foolish or crazy.

lawful tool (n.)

[1950s] (UK Und.) a tool used for committing a burglary.

SE in slang uses

In phrases

not the sharpest tool in the shed

[1990s+] unintelligent, stupid.