Trickery domain is more about making other people sneaky, but honestly it falls flat on its face both at its job and also when you compare it to other domains.
While i am not familiar with dnd5 p&paper honestly i find nothing about shar relating to stealth or sneaking.
Shar wipes the memories of her servants and likes to keep secrets... and her clerics are usually in medium if not heavy armor, with exactly zero need for Dexterity.
I do not think that the Trickery in BG3 has anything to do with Shar's "flavor" of "trickery".