I merely would like to hear other's opinions of this because it has come up two days in a row for me in two different games.
Often, for sake of expedience, there are certain assumptions made in character. Typically these are things like going to the bathroom, eating, drinking, sleeping, preparing spells at a set time, sharpening your weapon, etc..
Sometimes the assumptions can go larger than that. A request for a character to draw a map of where they explore by an NPC, can it be assumed it is done without mentioning it, because it is a re-quest and has a reward? What about sharing of knowledge or information? If the party sage makes a 30 knowledge check on a DC 12 creature, is it safe to assume they automatically tell everything they know to the rest of the party?
If not to any of these, do you play them out or require they be played out in character? Do you as a GM or player make it a point to mention eating rations or buying a meal? Do you ask if they are mapping or state you are doing so at the times you do it? Do you require they say what they know, or do you share the info as your character would?
What is the cutoff for what is assumed and what should be declared?
I hope it does not show what side of this discussion I am on, as I'm trying to present an unbiased question.