So you want it to be even better than monster radar, yet you want to conceal significant information from the player when that's not what the ability says it does. Some people are going to turn that into 20+ questions as they try to irk out every possible avenue for success or failure. Honestly now I think you're making it worse. Throw on how this manifests "in game" and how that irks some players and some DMs and it's just a mess.
What are you talking about?
It's monster radar only in the sense that you know the direction of your Favored Enemies within a one mile degree of certainty. And what am I concealing? The 3 rear guard scout troops are outside the Ranger's 5 mile range (although I guess I wasn't explicit in that) and he doesn't know about the wolves because his Favored Enemies is Humanoid, and wolves aren't humanoid. So it is great information, but it isn't 100 percent complete information. And both the character and player would know that.
It most certainly is not 20 questions. The DM is not limited to yes or no answers. Honestly I'm not sure what questions the Ranger's player would ask. The information I provided in my examples was everything that Primeval Awareness provides. If I missed something, then sure the player should point it out and, assuming he was right, I would clarify or add the missing information, but that certainly isn't 20 questions.
In game it manifests as a mystic ritual that "attunes your senses" so that you can sense your enemies within 5 miles. Why would that irk? Unless you want the "no magic" ranger, but that is not the base assumption for the ranger, which has spells by this level.