I am aware of this question detailing whether a character can tell what is depicted on a particular patch on a Robe of Useful Items.
It makes complete sense for the user to be able to tell what type of item they are activating otherwise it wouldn’t really deserve the moniker of useful.
What I want to know if there is any rules one way or another explaining whether the character would know the exact properties of the item the patch will create. For example when picking the random patches rolling a 31-44 determines a patch of a Wooden Ladder (24 feet long). Unless this patch has the words 24ft (or similar) written on it would the character know this was any different to the 10ft ladder available in the PHB list of items?
I have considered asking for an Arcana check to determine how much of the item’s nature the character wearing is able to establish but I also don’t want to be handicapping the player if there are rules that detail this scenario.