Why are small leaves an adaption in desert environmenr?

I would imagine it's because leaves are big to be able to absorb more sunlight for photosynthesis, so in a desert environment there would be too much sun and the leaves would need to be smaller because too much sun would mean an excess in heat, and that could damage the rate of photosynthesis by 'denaturing' the enzymes used in the process.

I hope this helps!