I would like to see the etiquette/posting guidelines updated to include recommended information.
Too many times a question is posted, and the first response is "where exactly, when, what type of food, what's your price range, any picky eaters, how many in your party, how formal?" All of these are critical to giving good advice, and too frequently they're left out. I wouldn't expect adding this to the etiquette to eliminate the problem, but it might cut down on it.
Most of these are also helpful when writing reviews, and posters should be encouraged to include these items where appropriate.