I would say the ritual dagger is one of the most important for witches. The cutting edge of the blade is meant to sever, divide and to create boundaries. As witches, we work with crossroads and "in-betweens" a lot. This makes the purpose of the dagger key to our practice. Beyond this, daggers can be protective when working with spirits that may not be benevolent.
Wands were taken from high ceremonial practices and didn't really become common until traditions like The Golden Dawn and Wicca became prominent. Wands focus and direct energy and it is believed the animistic power within the wand could be an ally if the practitioner developed a relationship with that spirit.
As a witch with their own practice, you choose your tools. Though there are some we consider standard, you don't have to work with anything you don't want to. Some witches don't use tools at all.