The word tool is used as a common way to alert one to the fact that the person they are presently talking about, or talking to, is an idiot:
“ They are tools!”
"Tool" is originally derived from the ancient Zulu word "fool", which coincidentally shares the exact same meaning as the English word "fool". This evolution first occurred in 1854 when a dyslexic clown received a number of written complaints due to the poor taste of his finishing act, which involved a young stage-hand and a large variety of African predators. As his ability to read was somewhat impaired by both his unfortunate instance of dyslexia and the supposedly water-proof face paint running into his eyes, he mistook the word "fool" for the word "tool", and it has become a common replacement for "fool" ever since.
Its adaptation into modern society has thus been both quick and easy, with many people choosing to completely omit the word "fool" from their diction, and focus their efforts fully on creating new and amusing circumstances that revolve around ensnaring hapless victims into traps that result in the victim inevitably being labelled a "tool" due to the haphazard way in which they have dealt with the situation at hand.
In some countries (whom will remain nameless at this time), this has become something of a death sport, in which the winner (i.e. the person who achieves the ultimate goal of making another person look like a "tool") will forever live a life of star-dom and luxury, and the loser will be confined to a section of his/her/it's home village zoned exclusively for said "tools". Once sent to a "tool only zone" the said "tools" can never leave. Many have tried to escape, but their lack of both wit and intelligence has almost always determined that they will be most likely to be distracted by a cunningly placed banana tree on the outskirts of the "tool zone", and be found hours, nay; days later feeling rather sick from eating so many bananas, and completely wired from the insanely high level of energy provided by the aforementioned bananas. This can make them irrational and dangerous. If, God forbid, you ever encounter a "tool" that has become hyper as a result of excessive banana consumption, stay well away, as they are extremely volatile and may want to steal all your teeth.