If I ask the party for a perception check and they all fail the party should be aware of their choices (in this case, perception is important). If I then surprise them with an enemy they are clear why that happened.
Alternatively in this case it’s to locate something, maybe they want to spend a luck point, flash of genius, or other similar ability.
DM quietly raises encounter difficulty in response to metagaming
DM should have rolled for the player secretly if they didn’t want to call attention.
Sometimes I ask for perception checks when there is nothing to notice out of the ordinary just to see them squirm.
It depends on your table, but I disagree.
If I ask the party for a perception check and they all fail the party should be aware of their choices (in this case, perception is important). If I then surprise them with an enemy they are clear why that happened.
Alternatively in this case it’s to locate something, maybe they want to spend a luck point, flash of genius, or other similar ability.
Better still, use passive scores since this is what they’re for. If you want your players to make active checks, give them a narrative reason.
But I’m also of the opinion that the more you run your D&D like you’d run anything Powered by the Apocalypse, the better it becomes.