In May last year, Te Puke High School mathematics head Steve Hose, 53, was stabbed with a 10cm kitchen blade.
A 13-year-old was taken into police custody.
And a Post Primary Teachers Association survey found that at least two secondary teachers were seriously assaulted by pupils every school day.
Teachers may now search students themselves as well as their "correspondence", which includes diaries, mobile phones and laptops.
The head of the Secondary Principals' Association, Patrick Walsh, welcomed the search and seizure guidelines.
"But I think ultimately where we want it to go is to amend the Employment Act to specifically include the power of search and seizure within legislation, which the ministry had shown its intention to do if [the Government is] re-elected," Mr Walsh said.
The Education Act allows schools the right to search but staff feared they could face disciplinary action if they carried out searches.
The guidelines would be an interim measure until the act was changed, Mr Walsh said.
Mrs Tolley said she had instructed the ministry to investigate changes.
Schools were given scenarios of when searches of students themselves, their bags or lockers and their cellphones or laptops would be appropriate.
The Government has also invested $60 million in the Positive Behaviour for Learning plan, which will give additional classroom management training to more than 7000 teachers.
As well, 400 schools received training in how to encourage positive student behaviour and more than 15,000 parents in at-risk families will be supported to build more positive relationships with their children.
SCHOOL RULES
* More than one adult present, with teacher ideally the same gender as the student.
* Parents or caregivers may be called.
* Teachers explain reason for search.
* Police can be called if situation becomes unsafe.
* Can search students, their diaries, cellphones and laptops.
