To what extent a GM should paint a full picture is definitely an issue at least when I come to running a game. Fundamentally I prefer character awareness or more specifically context to reflect somewhat realistically against the world we know. I suppose this is more of a day in the life perspective so for example a soldier or their platoon will have a clear job in front of them but wont be aware of the overall aims of the battle whether they are critical in achieving a specific objective or sacrificed for a larger aim. Likewise a rogue may have gained enough information for a lucrative opportunity but the consequences of his actions will inevitably pursue him over time. Hindsight is a wonderful thing provided players get a chance to learn from it and steer a game going forward.