I don't think that's a mistake, for two reasons.
Firstly, understanding how things would play out on a success gives a contrast to how things play out on a failure that aids in understanding the rules and/or playstyle.
Secondly, as established in the tangent with
@EzekielRaiden, such questions are viewed as necessary for establishing trust with the GM.
Perhaps, perhaps not. If it is simply "I feel like singing", no system I've ever played supports forcing a roll for that. If it is instead that one wishes to sing
with some further intent, then we talk about what they're going for. Perhaps they are trying to woo someone in order to get that person's help--a dapper swain serenading the beautiful youth in yonder tower. In DW, that sounds like a Parley roll to me--the thing the target wants is the singer's affection and loyalty (which is the singer's leverage), and the thing the singer wants is help with some other task. Leaving a trail of broken hearts is quite reasonable for many Rogues, Bards, and (perhaps surprisingly) Barbarians, at least based on the moves on their playbooks, so that seems quite reasonable.
Without further information--without enough context--I really cannot answer the question and would not expect a GM to give such an answer. Instead, the trust is established
in the doing.
As a good example, DW's Defy Danger move (described above) specifically says that on a partial success, you as the roller "stumble, hesitate, or flinch: the GM will offer you a worse outcome, hard bargain, or ugly choice." Now, one of the things my GM rules tell me is that the negative consequences of a move don't always have to fall specifically on the person who failed the roll--but as a general rule, when I consider doing that, I
tell the players specifically that the negative consequences might spiral outward from them. In combat, I find that's kind of assumed (e.g. if someone gets to safety, that may leave someone else exposed, players seem on board with that), but outside of specifically combat situations, it helps build trust if I tell players
in advance that the risk they're taking might spill out beyond them or might affect someone else, rather than the risk-taker themselves.
But even when it affects only a single person,
explaining yourself and
communicating are terribly important here. I don't stonewall my players--ever. I always strive to give them answers they feel are adequate when they use Discern Realities. When they get a partial success on Defy Danger, I try to provide a choice that is genuinely tough, something where they cannot simply calculate that one result is better than the other. That way, their choice is based on what they personally value, not what cold calculation selected. (I think this is an important design consideration for all games: if you offer diverse choices, make it so brute calculation cannot single out any particular options as consistently better or consistently worse, so that people have to make
qualitative choices, not quantitative ones.)
Communication, openness, consideration, and (for lack of a better term) "reciprocal" enthusiasm are the GM-side foundation of a healthy trust relationship between GM and player. My highest goal, always, is to cultivate and sustain my players' genuine, non-abusive, non-exploitative enthusiasm. Genuine means, of course, that the enthusiasm is real and not affected. Non-abusive means that each player treats the others as a human being worthy of respect, kindness, and support, not as a tool for their personal enjoyment, nor as a stepping stone to some other goal (as Kant would say, other humans are always ends in themselves, never a means to other ends.) Non-exploitative means they're upholding the spirit of the rules and the tone of the game overall, respecting the process and the other players, etc.--no pretzeling the rules to their own benefit but keeping them perfectly rigid against their opponents etc. (If the players want something ultra-favorable to them right now, they'd better be prepared for that logic to sometimes be ultra-favorable to their opponents! I find that just noting this once or twice is
ample to get players to avoid exploitative efforts.)
Naturally, the player has responsibilities too, but this post has already run probably twice as long as it needs to.
