Oooooh... I didn't knew that! It would be cool if that was more explicitely told in the editor, and it would also be cool if we could disable that option (just like the skills). :)
Now the engine displays item details in this description modal.
For the swords, I added:
"Collectible steel sword: when equipped, increases the player's attack damage (the strongest weapon). Breaks after a few hits."
But you gave an excellent suggestion about making weapon durability optional. That could be implemented as a simple checkbox.