en_tn/pro/17/27.md

uses few words

This refers to the way he speaks. Alternate translation: "speaks with few words" (See: rc://en/ta/man/jit/figs-explicit)

is cool of spirit

Having a cool spirit is a metaphor for being able to control anger. Alternate translation: "is able to control himself" or "is able to stay calm" or "does not become angry easily" (See: rc://en/ta/man/jit/figs-metaphor)