Taken from the Player's Handbook (p. 74)
Manoeuvring Attack. When you hit a creature with a weapon attack, you can expend one superiority die to manoeuvre one of your comrades into a more advantageous position. You add the superiority die to the attack’s damage roll, and you choose a friendly creature who can see or hear you. That creature can use its reaction to move up to half its speed without provoking opportunity attacks from the target of your attack.
My query pertains to the interpretation of how you can use this ability. For example, when I first used this ability, I told a friendly to move back from a creature, after he was already 30 ft away, moving him a further 15 ft away again. The reason for this was so that he would be out of range of the creature's breath attack.
So how exactly should this ability be used? Should it be merely to reposition a character (perhaps move a rogue around behind an enemy to get a backstab?), move a friendly into/out of the fight, or can I tell anyone to move 1/2 speed in any direction (not against their will, clearly, so I can't tell them to go jump of a cliff)?