In my experience, the "I try" locution often bleeds into a "Can I?" phrasing. Which I find irritating. I prefer the action declaration to be "I do", and then if the player's description needs to be wound back, the GM does that as part of the resolution process.Hmmmm, I'm not sure I really see much reason for this preference.
I'm not 100% sure I follow you here.That is, in practice, play in ANY RPG, certainly in most, even story games, revolves around something similar. There are things which PCs will learn in some fashion when they interact. I guess you could completely describe every possible defined element of every scene explicitly for the players beforehand, but my guess is that never really happens. Maybe its informal, maybe its even 'not really how its supposed to be done', but it kind of happens. That is the player says "My character seems to perceive a door here, I test that perception." Now, maybe in the above "all distinctions are explicit" there CANNOT be a point where the PLAYER 'discovers' that the door is locked, they would already know. So, maybe BW is like that, I'm not sure, I only played one variant a couple times long ago.
The canonical action declaration in Burning Wheel is I do . . . so that I can . . . or I will . . . so that I can . . . . This establishes a task, and an intent. But that task doesn't necessarily become part of the shared fiction. If the GM says "yes" then it does. If the GM says roll the dice! and the player succeeds, then it does. If the GM says roll the dice! and the player fails, then it is up to the GM to narrate what occurs, including how much of the task becomes part of the fiction. Probably some of it does - eg at least some of the PC's basic bodily movements, maybe some preliminary steps - and maybe even all of it does - eg the PC does open the locked door, but for whatever narrated reason that doesn't achieve the declared intent.
So at the moment of action declaration, the task is a purely hypothetical or posited or desired-but-not-guaranteed component of the shared fiction.
I approach 4e and Prince Valiant in much the same fashion.
But that doesn't change my preference about the verbal form of action declaration: I find the "I try" or "I attempt" locution insipid.
The same is true on the GM side: suppose in 4e I'm narrating the movement of some NPCs. The players probably have the capacity to interrupt that movement in some fashion. But I won't describe my NPCs' movement in terms of attempt. I say where they are going, and if the players interrupt in some fashion then I add in the corrected description.
Probably what's going on, in grammatical terms, is an implicit future tense: I'm opening the door or The NPCs are moving over here used to signal what is about to unfold, everything else being equal. A failed check, or interruption by a ranger using some immediate action, results in things not being equal and hence the description of what was to happen having to be revised.