Your ability to Steal defies belief. You can attempt to Steal something that is actively wielded or that would be extremely noticeable or time consuming to remove (like worn shoes or armor). You must do so slowly and carefully, spending at least 1 minute (and significantly longer for items that are normally time consuming to remove, like armor). Throughout this duration you must have some means of staying hidden, such as the cover of darkness or a bustling crowd. Even if you succeed, if the item is extremely prominent, like a suit of full plate armor,onlookers will quickly notice it's gone after you steal it.
Source: Pathfinder Player Core, p. 258
Bring Legendary Thief into a Pathfinder 2e game with The DM Screen.