To configure percona-nrpe plugins for mysql you will have to do 3 things viz :
1. define commands
2. Define service
3. Add commands on client to nrpe.cfg
First 2 can be easily done for help refer http://kedar.nitty-witty.com/blog/install-percona-monitoring-tools-for-nagios-mysql-plugins#comment-43181
I found less help available for 3rd point ie to add commands in nrpe.cfg on client side so here is sample nrpe.cfg for percona-mysql plugins !
command[check_mysql_service]=/usr/local/nagios/libexec/check_mysqld.pl -H 192.168.1.68 -u root -p xx -a slow_queries -w 44 -c 55
command[check_mysql_innodb]=/usr/local/nagios/libexec/pmp-check-mysql-innodb -H 192.168.1.68 -C idle_blocker_duration -w 60 -c 600
command[check_mysql_innodb]=/usr/local/nagios/libexec/pmp-check-mysql-innodb -H 192.168.1.68 -C max_duration -w 86400 -c 172800
command[check_mysql_active_threads]=/usr/lib64/nagios/plugins/pmp-check-mysql-status -H 192.168.1.68 -x Threads_running -w 20 -c 40
command[rdba_mysql_pidfile]=/usr/lib64/nagios/plugins/pmp-check-mysql-pidfile
command[rdba_unix_memory]=/usr/lib64/nagios/plugins/pmp-check-unix-memory -d -w 96 -c 98
command[check_mysql_deadlocks]=/usr/lib64/nagios/plugins/pmp-check-mysql-deadlocks -H 192.168.1.68 -i 5 -w 12 -c 60
command[check_mysql_connections]=/usr/lib64/nagios/plugins/pmp-check-mysql-status -H 192.168.1.68 -x Threads_connected -o / -y max_connections -T pct -w 80 -c 95
command[check_mysql_replication_delay]=/usr/lib64/nagios/plugins/pmp-check-mysql-replication-delay -H 192.168.1.68 -w 650 -c 600
command[check_mysql_processlist]=/usr/local/nagios/libexec/pmp-check-mysql-processlist -H 192.168.1.68 -w 80 -c 100
command[check_mysql_replication_running]=/usr/local/nagios/libexec/pmp-check-mysql-replication-running -H 192.168.1.68