NRPE returning no output?

command[check_recent_core]=PLUGINPATH/check_recent_core.sh --file="$ARG1" --freshness=$ARG2$

Spot the error? I only wasted an hour of my life and another 30 minutes of co-workers trying to figure out why I kept getting a "NRPE: No output returned from plugin" error in Nagios. The issue? $ARG1 is missing a closing “$”. *slams head on desk*