To reach or surpass the desired standard or performance or more generally to succeed, to have the ability to do something or to be adequate enough to participate or compete
It’s not clear exactly why we say cut the mustard. Some have proposed literal derivations, such as cutting down (harvesting) mustard plants. Others have suggested connections to the phrase pass muster (Pass muster means reach an acceptable standard) when a soldier gets approval after troops are assembled together for inspection.
Or, mustard being small and shiny, requie high skill to cut it with knife and hence, the idiom is highlighting the expertise require to perform such an act. Evidence for these origins are wanting.
Example
He was a great player, but he retired sometime ago. We’ll have to see if he still cuts the mustard
Athletes who can’t cut the mustard don’t make the team.