In the setting that I've created, the party will be spending time around a world tree. The tree is extremely large and has a large number of town sized bird cages (flowers of the tree that never detach and buildings within are primarily made from tree parts), inhabited solely by flying races and as a result very difficult to traverse without flying. Whilst possible through lifts/towed vehicles used for transporting items, expecting this of non-flying races (or those that are no longer capable) is unrealistic so the locals designed and give out "Prosthetic Wings" that are powered from the magic of the tree.
Later on the party will have a chance to get an airship made of part of the tree, similar in stats to a standard Sailing Ship from Ghosts of Saltmarsh, which these will also be expected to work with. In this context they're to be expected to allow melee combatants to fight flying threats which will be run into travelling and allow safe repairs without landing.
Wonderous Item, Common
This item appears to be a small wooden seal that magically attaches to anything it's pressed against. The seals magic only works when it has been within 200 feet of at least 500 lb of World Tree Wood within the last 30 seconds.
You gain transparent wings on your back and claws formed over your feet similar in appearance to those of the crafter, granting 60 feet flying speed (unusable with medium or heavy armour), 1d4 unarmed damage and the ability to grip and manipulate with your feet as if they are your hands.
This item isn't attuned as I don't want melee fighters to be disadvantaged by the requirements, though they will be given before players have enough items requiring attunement to fill their slots. Along with this, races that start with flying are not allowed for player characters.
Is this an understandable description, useful for the intended purpose, and un-abusable? I'm open to frame challenges about both of its intended uses.