what does "be incisive with" mean ?
Johnson had been incisive with Kilduff. Watching him in the stateroom, his wife had thought him "absolutely a graven image. His was a face that looked carved in bronze." He had known exactly what he wanted: he wanted the acting press secretary, whose calmness at Parkland had impressed him, to take the lead in setting things up for Sarah Hughes. To the new President he seemed an ideal liaison man, a vigorous Kennedy aide and an expert in mass media. As Vice President he hadn't been told that this trip was supposed to be Mac's swan song