The phrase "tougher standards" refers to stricter rules or higher expectations that need to be met. It means that the requirements or criteria to achieve or succeed in something have become more challenging or demanding. Full definition
The Common Core initiative calls for implementing fewer, tougher standards for literacy instruction. (ascd.org)
When analyzing mutual funds, it is often very difficult to identify the fees even with tougher standards being enacted against fund managers. (insuranceandestates.com)
Parents are pushing for tougher standards on nutrition in school food. (washingtonpost.com)