The guidelines say that when staff believe a student has a dangerous item concealed in clothing or bags the most straightforward approach is to question the student.
"Staff may ask a student to hand over any item and, in most cases, a student questioned by staff will admit to possessing such an item and will hand it over," the guidelines say.
"The decision to search should not be made without good reasons and should follow fair, clear and safe procedures."
They say searching students and confiscating their property can be challenging for boards of trustees, principals and school staff.
"Searches are an intrusion into students' privacy and can also amount to an additional sources of difficulty in already tense situations."
Mrs Tolley said the $60 million Positive Behaviour for Learning plan was already seeing "great results" in dealing with difficult students.
More than 7000 teachers were receiving additional training in effective classroom management and staff from 400 schools were receiving training in promoting positive behaviour.
"Other support for schools includes a new rapid response service following the most extreme behaviour incidents and an Intensive Behaviour Service to target the most complex and challenging students," she said.
- NZPA