A full name and birth date are the minimum requirements. A photo can strengthen the precision of the work, and for very targeted cases, a personal item (something you own, not something taken from someone else) can be incorporated as an anchor for the protection.
For home protection, knowing the address and a little about the layout or history of the property helps me tailor the ritual more specifically.
Nothing invasive is ever required — if you're only comfortable sharing a name, that's enough to begin.