Unlike all the other "If you fail, you must either ... or ..." effects, this one does not contain the word "must", which implies that you can choose to place 2 clues on your location even if you have none.
The section "Must" in the rules reference says: "In the absence of the word “must” while choosing among multiple options, any option may be chosen upon the resolution of the effect—even an option that does not change the game state."
Or am I missing something? Could this be an oversight by the designers?