I’d call that a skill, rather than a character trait. The closest thing I can think of to a beneficial but non-admirable character trait is high-functioning sociopathy; but that’s at least touching the borderline of mental disease, if not clearly crossing it. Perhaps “charming ruthlessness?” But many would consider e.g. Erwin Rommel virtuous in that respect.
I’d call that a skill, rather than a character trait. The closest thing I can think of to a beneficial but non-admirable character trait is high-functioning sociopathy; but that’s at least touching the borderline of mental disease, if not clearly crossing it. Perhaps “charming ruthlessness?” But many would consider e.g. Erwin Rommel virtuous in that respect.