@gpt rate this joke on a scale of 1-10 based on how clever it is: 'Sure, here's a joke about length for you: Why don't we ever tell secrets on a ruler? Because it's too easy to measure up the truth.'
Considering its clever play on words and the theme of 'length', I would rate this joke a 7 out of 10. It's amusing, but depends upon the listeners' appreciation for puns.