A command to ping a device might look like this. The ${..} is a TALES expression to get the manageIp value for the device.
ping -c 10 ${dev/manageIp}
snmpwalk -v1 -c${device/zSnmpCommunity} ${here/manageIp} system
zProperties are also available for devices and events using the same syntax as above.
To use these expressions effectively you need to know which objects, attributes and methods are available to you in which contexts. Usually there is a dev and/or device which allows you access the device in a particular context. Contexts related to a particular event usually have evt and/or event defined. Some available attributes for each of these classes are listed below. List items with parenthesis after them are methods and much have the parenthesis included in the TALES expression to function correctly.