Flying Tool is a standard ninja skill which allows a ninja to summon an assortment of items or weapons that have been stored using Fūinjutsu, typically they are stored within scrolls. When needed, the owner will activate the seals releasing their item or weapon of choice. Puppets can have these hidden inside various compartments as a means of increasing their own killing potential as well as hiding potentially useful weapons from the opponent's sight.
Sources
Naruto Shippuuden episode 133
Naruto Shippuuden episode 19
