Not enough information.
In my kids’ school, there are a few “tough” teachers. The problem is that one or two of them are “tough” in ways that directly violate school policy. Example: school has a standard late policy with substantial deductions for late assignments. One of the “tough” teachers just gives zeros. Is she setting high expectations? Yes. Is she a good teacher because of this? No.
I expect that teachers who are tough in thier expectations for kids will be superstars in delivering on parent’s expectations too. A teacher who is a hard grader and gives assignments with short time-frames in order to challenge the kids must be almost instantaneous in grading and error-free in both grading and communication. A teacher who sets a high bar on student behavior had better be the sweetest, most polite (yes, m’aam, not calling me by my first name

) teacher in the school.