Hickey is not leaning on the dictionary. The specific definitions he lays out for tool and automation make up his argument, not the words themselves. Saying "no, tool can be these other things" misses the point by a considerable distance.
So he's stipulating a definition of the word and then saying LLMs don't meet it. A more truthful title would be, "LLMs are not tools in my narrower, idiosyncratic sense of the word." Fine, but so what?