Worthiness for the greater good (or bad)
Smart weapons are desired already. A weapon (and ammo) only your team can use is invaluable. This goes for large things like war, to smaller things like police/criminals and even smaller to a household with a hunting rifle and you don't want it active when a kid finds it.
An AI could assist in a lot more. Depending on the amount if sci-fi, it could aid in the effectiveness of the weapon. When to use armour piercing deadly rounds or when to use stun. These days they can even make them more accurate. In a sci-fi setting this could be further enhanced.
Not just weapin power, but it can also communicate with other equipment or the user, making them near instinctively aware of their surroundings, their strengths and limitations.
If you already have an AI, you can impose restrictions to your world view. Upholding justice or protect the innocent? When is someone guilty or a danger enough to get shot? Should it still work if a person tries to shoot their cheating partner? Should a disarmed opponent be shot or not? What if several of these conditions collide?
A "worthiness" implementation can discern intent and many other variables. The sentience will make them able to learn and adapt, as strict rules can lead to failure in it's intended task. All this will make sure the weapons are handled according to their power and towards a certain goal. I would say it's not a stretch to have such weapons.