Since joining the Official Idealized Rationality Organization as a fresh novice six months ago, you have been training and studying hard, and today you are ready to take your exam to advance to the first rank of recognized skill and knowledge.
You expect the test to be difficult. Here in the Future, card-carrying Rationalists are widely known to be formidably effective, clear-thinking people. Rationalists are capable of impressive feats individually, and accomplish miracles when working in groups. Part of cultivating such a strong reputation, obviously, involves setting high standards.
You step out of your flying car, enter the testing center, and take your seat. The proctor hands you a thick sheaf of test questions. Turning the first page, you read the first question ...
(What sorts of question would you hope to see on such a test? If not "test questions" per se, what other sorts of requirements would make sense?)
(Another way of looking at this might be: design a test that you would be proud to say you passed.)
The answers suggesting "this shouldn't be a test you can study for" seem very misguided. This is a yellow belt, not a black belt. If you think you can become a card-carrying Rationalist without studying books, you are mistaken.
I would expect a battery of short-answer questions, maybe 6 hours/75 questions. Prove the Pythagorean Theorem. What is Bayes' Theorem? Is Pascal's Wager accurate? What impact do human emotions have in decision making? If humans evolved from monkeys, then why are there still monkeys? Was George Washington a myth?
There is an aesthetic desire for a more flashy test, a gom jabbar for the rationalist. I would expect that would be an intermediate test between the yellow belt and the black belt. The various "Explain this mysterious system" questions are good, so I'll suggest some puzzle where "what do you think you know and why do you think you know it" is the key to the solution.