[There's a basic note that gives instruction that the 'power' activates upon the user 'willing' it to do so, including the details of the power as well as the name of the item:

Ligma Crossbow - Each arrow fired from this crossbow is automatically replaced because they're made from magic, even if the crossbow and arrow itself looks like a normal, everyday one. More durable than your standard crossbow in that if a titan stepped on it, it'll still be around. Is especially effective against flying units.

There is also a personal note sent along that reads:

"Donnez à ces oiseaux la raclée qu'ils méritent. Bonne chance!"]