In theory your ritual tools should be kept to your self unless being used in a group ritual. (Minus the theory of a friend comes over after school and asks to see yours as reference in making their own.) They are not objects you would need to have at school with you.
With the issues schools are currently facing as far as crime and offenses being committed in those atmospheres, the laws and school policies are changing as well. And even getting to the point that a pencil could be viewed as a weapon depending on how it is being used. Wands typically don't exceed 13 inches in length, though are much bigger than pencils and depending on how it's made could certainly be viewed as a weapon.
You should stop into your guidance counselor's office and see what your school policies define as a weapon, and what could be conceived as such. Then simply flat out ask about the item you wish to take to school (though you don't have to refer to it as a wand if your peers or teachers are not aware of your pagan practices).
Although to be on the safe side I would recommend that you leave your wand and other various tools at home, and if you have to transport them to school for an after school activity, leave them in your car or locker until you leave. No reason to give someone a reason to think that you may or may not be carrying a weapon. And your school's policies are better to check and abide by than our opinions alone. ;)