Is there any tool available to write Irules

Not sure I f I can get some help on this irule:

I have a Irule as below:

when HTTP_REQUEST { set uri [HTTP::uri] }

when HTTP_RESPONSE priority 400 {

 if { not ($uri starts_with "/cip/SpotfireWeb/AjaxService.asmx/NeedsRefresh") } {
            set lat [clock seconds]
            if { not ($uri starts_with "/imcadminhome/services/userSessionServerPing") } {
                 HTTP::cookie insert name "PD-L-LAT" value $lat path "/" domain ".ironmountain.com" 
                 HTTP::cookie secure "PD-L-LAT" enable
                 log local0. "\[HTTP::cookie \"cookie\"\]: [HTTP::cookie "cookie"]"
            } 
            HTTP::cookie insert name "PD-L-LAT" value $lat path "/imcadminhome" domain ".ironmountain.com" 
            HTTP::cookie secure "PD-L-LAT" enable
            log local0. "\[HTTP::cookie \"cookie\"\]: [HTTP::cookie "cookie"]"
 }

}

This iRule is to delete all session cookies from browser so that browser doesnt remember anything about old session. We have a /pkmslogout.html page that currently has javascript running on it to delete session cookies but we trying to achieve that throught the irule so that once we logout from the application , all session cookies get expired. Also I am trying to log it in the log file but only seeing below logs:

Nov 25 09:39:52 kan-qa-vf5-a info tmm[28093]: Rule /Common/PD-L-LAT-no-heartbeat-admin-iRule-Modified : [HTTP::cookie "cookie"]: Nov 25 09:39:52 kan-qa-vf5-a info tmm[28093]: Rule /Common/PD-L-LAT-no-heartbeat-admin-iRule-Modified : [HTTP::cookie "cookie"]: Nov 25 09:39:52 kan-qa-vf5-a info tmm[28093]: Rule /Common/PD-L-LAT-no-heartbeat-admin-iRule-Modified : [HTTP::cookie "cookie"]: Nov 25 09:39:52 kan-qa-vf5-a info tmm[28093]: Rule /Common/PD-L-LAT-no-heartbeat-admin-iRule-Modified : [HTTP::cookie "cookie"]: Nov 25 09:39:53 kan-qa-vf5-a info tmm[28093]: Rule /Common/PD-L-LAT-no-heartbeat-admin-iRule-Modified : [HTTP::cookie "cookie"]: Nov 25 09:39:53 kan-qa-vf5-a info tmm[28093]: Rule /Common/PD-L-LAT-no-heartbeat-admin-iRule-Modified : [HTTP::cookie "cookie"]: Nov 25 09:39:53 kan-qa-vf5-a info tmm1[28093]: Rule /Common/PD-L-LAT-no-heartbeat-admin-iRule-Modified : [HTTP::cookie "cookie"]: