The phrase "sure schools" refers to educational institutions that are known and trusted for providing a good education. These schools are considered reliable and dependable choices for students. Full definition
You also want to make sure the school doesn't use a behaviour system that involves shame - deliberately drawing attention to the child in a negative way. (bounty.com)
Make sure your school district websites are among the best school websites on the Internet. (schoolwebmasters.com)
And how can we make sure those schools get help? (schoolsweek.co.uk)