$ /opt/csw/bin/sudo /usr/sbin/swap -s
total: 4695344k bytes allocated + 7045216k reserved = 11740560k used, 2827352k available

$ uname -a
SunOS msuxsup1 5.10 Generic_125100-09 sun4u sparc SUNW,Sun-Fire-V215

$ /opt/zabbix/sbin/zabbix_agentd -V
Zabbix Agent (daemon) v2.0.5 (revision 33558) (12 February 2013)
Compilation time: Mar 27 2013 20:26:43

$ /opt/zabbix/sbin/zabbix_agentd -t system.swap.size[,pused]
system.swap.size[,pused][,pused] [d|0.000000]
$ /opt/zabbix/sbin/zabbix_agentd -t system.swap.size[,pfree]
system.swap.size[,pfree][,pfree] [d|100.000000]
$ /opt/zabbix/sbin/zabbix_agentd -t system.swap.size[,total]
system.swap.size[,total][,total] [u|8596676608]
$ /opt/zabbix/sbin/zabbix_agentd -t system.swap.size[,free]
system.swap.size[,free][,free] [u|8596676608]

I found the solution. Please look comments for getting more information.