Sword
Description: A double or single edged sword, with a blade longer than an athame. There really isn't a sword in our tradition, so if we use one in circle it doesn't have to have any particular attributes. In fact, I think that the use of the sword comes more from the Hermetic Orders and the Ceremonial Magician's traditions, and was simply incorporated into Wiccan rituals because often practitioners were members of both groups.
Element: Air - to signify the energy of thought, this comes to us from the Tarot cards, as mentioned before.
Uses: The use of swords is more limited in circle than the use of the athame, mostly because of it's length. We use it to cast the circle, for Drawing Down the Moon (by laying it on the HP's shoulders in our tradition) or we also use it to ritually signify passing on the leadership of the coven at certain times (by "passing" the sword ceremoniously to someone). We do not have a sword at every ritual, and this tool is certainly not a "required" one.