How about if you place a tool on a bench with an ender orb it will enhance your tool and restore its health by 25%
And things will break 10% - 30% faster, and it will last 10% longer.
But making ender orbs a 1/3 drop rate wold make this worth it, while making endermen more powerful.
And make ender blocks, which will only break with an enhanced tool. :D