https://www.zabbix.com/documentation/2.4/manual/appendix/items/vm.memory.size_params

Lists the parameters that can be used with the item vm.memory.size, however

https://www.zabbix.com/documentation/2.4/manual/config/items/itemtypes/simple_checks/vmware_keys

only shows [<url>,<uuid>] as parameters for this item.
Please extend the documentation to include at least the right parameter field and the chosen default parameter.