The noun concision means briefness or brevity. If it's taken you only two minutes to describe all nine seasons of your favorite TV show, you've done it with concision.
In the 1500s, concision meant "a cutting away" or "a mutilation," from the Latin concidere, "to cut off or cut to pieces." For some wordy writers, an editor's emphasis on concision (cutting out extra words) might feel as violent as that, but really it's simply a matter of becoming more concise, or short and to the point.