Miraculous tools or Miraculous weapons are special tools that come with Miraculouses. Whenever a Miraculous holder transforms, they possess a tool specific to whichever Miraculous they have.
For the sake of seeing and communicating with kwamis, a mage in ancient times created the Miraculouses, magic jewels. At the same time of making Miraculouses, the mage created tools to go with each Miraculous.
Besides their Miraculous weapons some wielders also can fight with additional weapons like Tentomushi with her nekode, La Coccinelle with her rapier, and Ladybug with Kagami's saber in "Riposte". Or some weapons can split apart like Cat Noir's staff showing that they are capable of dual wielding.
When activating their fusions powers Miraculous holders can dual wield as well like as Dragon Bug, Ladybug fought with both her sword and yo-yo.
Each tool is a different object, like Ladybug's yo-yo and Cat Noir's staff. There are many types of tools, including toys, musical instruments, and weapons. Usually, the tool is a size that can easily be carried by hand, and some tools can be worn when they aren't in use, such as Ladybug wrapping her yo-yo around her hips or Cat Noir having his staff attached to his back.
Sometimes when fusion powers are used Miraculous tools can change color like how the jump rope of the Mouse Miraculous changed from orange, red and black upon the Mouse Miraculous being fused with the Ladybug, Cat and Fox Miraculouses.
Many of the tools are used as weapons, being handy for offense and defense. The tools are almost indestructible, it takes a powerful or magical force, like Simon Says' command card, to break them. Some of them are capable as means of transportation, like when Ladybug can swing from place to place with her yo-yo and Cat Noir can vault himself with his staff. Tools can also have technological features to them, including a phone, a GPS, and a search engine. Every individual Miraculous tool has the capability of communication. The features of the Miraculous tools "update" in accordance with the technologies of the time. It is unknown if all the tools work the same it has been shown that Ladybug’s yo-yo and Cat Noir’s staff can be used as a breathing device.
For some Miraculous holders, they need the tool to use their superpowers. For example, Ladybug tosses the yo-yo into the air whenever she utilizes Lucky Charm. Rena Rouge plays her flute to create illusions. Carapace holds up his shield to engage Shell-ter. Queen Bee spins her spinning top and catches it to use Venom.
However, seen in "Sandboy" it appears that some of the tools have a weakness when being used to summon their powers the holders can't use them attack or defend themselves. If attacked by an akumatized villain during the process the powers will be cancelled out or if a holder becomes separated from their weapon they can't summon their powers.
Some of the weapons are capable of storing and holding others things like tracers, ear communicators or with Marinette storing letters in her purse and were moved into her yo-yo when she transformed in "Backwarder". When the yo-yo or staff is transformed into their phone mode, they are capable of taking photographs and when the holder is detransformed the photographs will transfer to the holder's regular phone like with Adrien's phone in "Oblivio".
When under the powers of fusion some weapons can be combined with other miraculous superpowers. As seen in "Miracle Queen", when Ladybug as Dragon Bug used her yo-yo combined with the Water Dragon to make a water sphere shield.
When Théo Barbot and Chloé Bourgeois get akumatized into copies of Cat Noir and Ladybug respectively, they possess identical versions of the original superheroes' tools with the same features.
Lila Rossi's akumatization into a replica of a Fox Miraculous holder includes her possessing a copy of the flute.
The real flute in "Sapotis" has the same abilities as Volpina's flute, but Rena Rouge's flute can only create one illusion as opposed to Volpina's many illusions. After the flute has been used once, the Fox Miraculous starts to time out, but Volpina's Miraculous doesn't.
As depicted in art in "Ladybug & Cat Noir", Herakles had a spear and Tomoe Gozen had a naginata, although it's uncertain if these weapons are the tools to their unknown Miraculouses or additional weapons.
In "Reverser", "Queen Wasp", and "Mayura" it is revealed that the Miraculous tools can be used for breathing underwater, even if Cat Noir and Ladybug are not in aqua form.
Miraculous tools can also be destroyed by Cataclysm as seen in "Mayura".
Also hinted in "Mayura", Ladybug wanted to used Hawk Moth's cane to track him implying that Miraculous tools can be used to find their owners when lost, although Hawk Moth detransforms before they can.
In "Oblivio", it's revealed that the weapons when converted into their phone forms have a user's guide.