The conclusion of my question Is it possible to have a planet unsuitable for agriculture? was that the most plausible reason for preventing agriculture from developing (beside nomadic herding) was having arid planet with erratic rainfall.
Is arid planet where climate is very unpredictable possible?
The effect I want is that farmer never knows when and how much rainfall there gonna be on his fields, it might be too much, just right, or none at all, and every year is a gamble.
If that kind of planet is possible how would it look like (moon(s), oceans, landmass, axial tilt, atmosphere, placement in the star habitable zone).