In case of 3rd nerve palsy EW nucleus parasympathetic action of miosis will not be present but M3 receptors present in eye will respond to 1% and 0.1% pilocarpine easily resulting in miosis .
Remember Phenylephrine,Adrenaline, Cocaine…
were used to Confirm Horners Syndrome in which Miosis is a feature…So on application of these 3 things our eyes will Dilate ( so,these 3 are used to check whether our pupils will dilate or remain permanently miosed) .
Pilocarpine on the Other hand will constrict a pupil …So it is used to confirm a Dilated Pupil ( i e even after application of Pilocarpine did the pupil remain dilated or did it constrict)
Have you watched neuro video - pupil?
Flowchart of Anisocoria?