One thought on Story Now GM-ing ---
As a GM, plan and prepare to radically increase your overall transparency and level of forthcoming information relating to the game world.
Picture your classic, "stingy with info" dungeon crawler GM, and how forthcoming that individual typically is with info regarding the game world.
Multiply that level of forthcomingness by 4x. Then take that result, and multiply that level of forthcomingness again by another 2x or 3x.
Once you're there, you're in the neighborhood of appropriate GM transparency for Story Now play.
Now, this doesn't mean that you can't hold back a small handful of perhaps crucial "secrets," which should be tied to the "fronts" progressing along in the game world, some of them even outside the view of the players.
But those "fronts" should be generally tied to player/PC concerns (as often as possible), and should be part and parcel with your prep, and in most cases should be telegraphed over time as part of "soft" moves in cases where the GM is asked to make those moves.
And those secrets/fronts should also be open to revision based on what's happening in the gamestate now, and furthermore any secrets/fronts should not be used unilaterally to negate player success. If a PC makes an attempt, and after the roll of the dice a success is indicated, your "secrets" cannot negate player success. If anything, any "secret" that would negate player success should be telegraphed to them as part of the framing.
Clearly telegraph to the player if success is even possible given the current fictional framing, and clearly telegraph how they might succeed on their intent as well as the stakes of failure. The point is that because the current state of the fiction carries so much weight in giving players the ability to make action declarations (and potentially trigger moves), players need to have an abundantly clear picture of how their character would fully assess the situation.
Classic example --- picking an ancient lock on some chest or whatever.
"Well, this looks something like a multi-layered mechanic lock like something you'd see in the movies made by an Italian Renaissance philosopher. Your basic pick locks aren't going to get the job done here. Perhaps you could try smashing it, but there's no guarantee that you'll retrieve the contents unharmed. You recall that your father's library has clues related to this kind of device. If you can successfully transport it there for more study, there's a decent chance you can get answers to opening it. But that means hauling this heavy chest back through the ruined castle, and you and the comrade carrying it are hardly going to be able to fully defend yourselves while doing so. Smashing it certainly will at least let you see the innards, but there's no guarantee you'll get what you came for.
"What do you do?"
Notice at no point have I-as-the-imagined-GM negated the player's intent to Open the chest and discover its contents. There's nothing that says you can't imagine a situation that players can't necessarily overcome immediately. Though in some systems, there might be player-side moves/resources that may, in fact, mean that the chest is openable immediately --- "Hey Mr. GM, I have this nifty 'Dungeoneer Gadget' move that says it's possible that I have seen a similar style of lock and might have the tool I need. I want to search through my tool bag and see if it's there."
GM: "Sure! Just be aware that as you search for it and try to find the exact right device for this case, there's definitely sounds of footfalls approaching from the darkened corridor on your left. If you take too long to look, there's a decent chance you're going to get intruded upon" (i.e., framing consequence of failure, setting up the next soft move to follow if player-activated move doesn't succeed).
Get in the habit of clearly setting scenes, clearly setting stakes, clearly giving information that is actionable by the character within the fiction, and do it with an eye to addressing character concerns. The point of getting into this mindset is ultimately to allow players to do just that -- actually address their character concerns. And players can only do that when they're operating with a transparent picture of the situation and what's at stake.