Perception stuff is always tricky! DW includes one way by default, but honestly, custom moves are your friend here. Adam's is pretty good.
In my current World of Dungeons game, I use two methods.
1. Tell them what's obvious, including tell-tales of secrets if there are any.
2. When they take the initiative and investigate something, I ask them how they do it. Then roll+WIS (usually). On a 10+, I tell them everything they could reasonably know or intuit, based on who they are and what they're doing. Character class matters a lot; it's the lens through which information is passed. On a 7-9, they make some progress but it's a half measure. I tell them something true, but don't elaborate. If there's trouble, I can bring it (often, curious monsters, guards, time slipping away). On a miss, trouble manifests fully, and this avenue of investigation is a dead end for now. Nothing to see here, try another way.