The information about this skill:
Exchange carry-on items with the target.
Note:
Even if one party does not carry any items, it will succeed.
Carriers exchanged between themselves and their targets are usually returned after the war, but the battle against wild pokemon will still be exchanged permanently.
......ellipsis
When my pokemon noticed the wild pokemon held something, I tried to use this skill to exchange item with it (my pokemon held nothing) , the battle message showed that my pokemon got the item but in actually my pokemon didn't get this item and the target no longer held this item, either.
So the method about this skill is not runnning properly.
I think may this is a bug?