Vanilla behavior in 1.11+ mc version will allow you to avoid dying if you will hold Totem in hand when Dying. This is really not useful as most of the time you won't know when you are gonna die. This will allow for the totem to be one of the most useful things on your server without being overpowered or being a useless new gimmick. Now there are 3 new options:
Option 1: Totem can be automatically consumed on death event from your inventory despite if you are holding it or not.
Option 2: To avoid option 1 being an overpowered feature, as a player could have a bunch of totems in inventory, cooldown system was implemented and you can limit how often a player can use a totem. The default is every 10 minutes. BossBar will be shown with time left until you can use totem again. You can toggle the bossbar on/off with /cmi totemtoggle command.
Option 3: By using this you will need to actually use the totem. On totem usage, you will have 10 sec (default value) window, during which you can die and you will be resurrected. Totem will be consumed on usage and won't be returned to the player even if the resurrection is not performed. This feature requires more strategic planning than just having totem in inventory.