An interesting look at the 4th dimension of time....
I, as a GM, cannot see into the future. Thus I cannot give you "all the things your character should have known about the situation" before those thoughts have even been created in my head. Literally all my notes say is "There is a chest with 5 healing potions in it and a DC 15 lock". You, as a player, can ask me 1000 detailed questions on the chest that I can make up answers to before you make the check.
What kind of wood is it made from? Oak
What metal is the lock? Steel
Does it look rusted? Not particularly
What are its exact dimensions? 10X8X8
If I lick the wood what does it taste like? Moldy oak
Etc...
Then you say your character is going to try to unlock the chest. In this hypothetical we don’t seem to be observing the flow of play described in the How to Play section of the 5e rules. According to that, it is your responsibility as DM to describe the environment. My responsibility as a player is to describe what I want to do, not to uncover the details of the environment by asking 1000 detailed questions. If all you put in your notes was "There is a chest with 5 healing potions in it and a DC 15 lock,” then you will need to do some improvisation to fulfill your responsibility of describing the environment. Which is totally fine if you like to do it that way, but if your improvised description didn’t include rust on the lock, then rust on the lock shouldn’t be given as a reason my check failed
after the fact.
IF there was no reason for you not being able to keep trying until you get it....then I would roll a die behind the screen (1-20) and narrate how it was a simple twist of the wrist or that someone had shoved a copper piece in the mechanism and it took awhile but you got it open...then give you the potions.
That wouldn’t be immersion breaking, but I wouldn’t care for it for other reasons.
OR
If there is a reason for you not being able to keep trying (EVEN IF THAT REASON IS ME, THE GM, DECIDING YOU ARE BREEZING THROUGH THE ADVENTURE AND I NEED TO UP THE DIFFICULTY A BIT)
And again, here’s the problem. If the reason I can’t decide is that you decided so, it ruins my ability to make predictions about the likely outcomes of events, because I can’t read your mind.
then I would tell you to roll the dice and see if you can get the chest open. You get a 2 and fail the check. Then I have to come up with some reason to narrate to you why there is a delay in your trying again (because otherwise I would have used the other narrative only option). Yea, the copper piece in the slot won't come out without taking the lock apart completely.
At this point you can try something OTHER than just rolling again. Maybe the wizard has a grease spell, or shrink powder, or maybe the barbarian just whacks it, or maybe you disassemble the lock and it takes a short rest to get it open. There are a LOT of other solutions to getting the goodies that doesn't include you just rolling over and over until you succeed.
The words spoken between GM and Player do not represent the entirety of the information the character observed nor does it represent the entirety of all the actions the character took.
If your character is picking a lock...they are literally doing everything in their power (at the moment, however long that moment might be) to open the lock. If the lock was rusty, they are adding in some oil. If it needs more force they are using the correct tools. You don't have to, as a player, narrate that you are oiling the lock or that you are using the #3 bent hook instead of the #7 spring hook because its just naturally assumed.
Yes, I understand the reasoning behind this style of DMing. I still find it horribly meta.