Hello Aternos Team!
I have a plugin called Durability Alert in which it alerts the player if their item Armour or Tool is about to break.
DurabilityAlert is a plugin that notifies the player when their items are low on durability.
Works for: All armour, Pickaxes, Axes, Shovels, Swords, Hoes, Fishing Rod, Shears.
The warning can be toggled (with the command /durabilityalert toggle) by each player so that it's not forced on everybody.