Negative is the gag, if it is brought by the players in order to get laughs from the audience instead of the scene to be of service. A gag may have a previously thrilling scene for the audience completely uninteresting and these can then be only terminated. With "gagfreudigen" players it is difficult to perform serious or prolonged scenes.
Positive use: In abbreviated form or to end a scene.
Especially when short forms of the gag is usually absolutely a beat.