I'd like to link here another issue which similar to this one in a similar aspect: the agent should report "something" to the server before the correct stop.
It's ZBXNEXT-444

Hello,
we keep being notified by hosts going down because sysadmin are restarting them.
I opened this ticket to be able to stop notification when the agent is turned off.

I solved the problem by changing the init scripts (RedHat Only for now) to SEND a message through zabbix_sender.

This way we can use the value to make the trigger go off only when the server is genuinely down and not then people are working on it.

# functions
start() {
        if [ $RUNNING -eq 1 ]
                then
                echo "$0 $ARG: $BINARY_NAME (pid $PID) already running"
        else
                action $"Starting $BINARY_NAME: " $FULLPATH

                [ ${ENABLE_SENDER} -ne 0 ] && $SENDER -z ${ZABBIX_SERVER} -p ${ZABBIX_PORT} -k ${KEY} -s ${HOSTNAME} -o ${STARTED} >/dev/null
                touch /var/lock/subsys/$BINARY_NAME
        fi
}

stop() {
        echo -n $"Shutting down $BINARY_NAME: "
        killproc $BINARY_NAME
        RETVAL=$?
        echo
        if [ $RETVAL -eq 0 ]
            then
                [ ${ENABLE_SENDER} -ne 0 ] && $SENDER -z ${ZABBIX_SERVER} -p ${ZABBIX_PORT} -k ${KEY} -s ${HOSTNAME} -o ${STOPPED} >/dev/null
                rm -f /var/lock/subsys/$BINARY_NAME
        fi
        RUNNING=0
}

Will post soon my solution to the forum.

The current solution sends a message from the init script, but something slighlty more elegant might be to have a "post_start" and "before_stop" directory where you can drop in scripts. This way you can easily create other useful scripts using the API that can be used to do all sort of magic.

What about having a new status like 'Zabbix-Agent status' for action conditions and filters, similar to 'Maintenance status'?
That way one could use for example an action condition 'Zabbix-Agent status not "stopped"'...

See also ZBXNEXT-1514 and http://zabbix.org/wiki/Docs/simplify_ad_hoc_maintenance