tough on (someone or something)
Particularly strict, stern, or severe with someone or something. You need to get tough on your kids, or they're never going to respect your authority. The new administration said it was going to be tough on political corruption. I know you think we're too tough on you, but we want you to reach your full potential.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
*tough on someone
severe and demanding in dealing with someone. (*Typically: act ~; be ~; become ~; get~.) My boss is very tough on me, but I need the structure and discipline.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.