Enemy Insight (5e Spell)
From D&D Wiki
Choose a creature that you can see within range. The target must make a Wisdom saving throw. On a failed save, you gain a general idea of the creature's combat capabilities as compared to your own. At the DM's discretion, you may learn about other pertinent capabilities. The target gains no inherent knowledge that you cast the spell, or that it was being targeted by your spell.
Once you cast this spell on a specific creature, regardless of the saving throw outcome, that creature becomes immune to your enemy insight spell for 24 hours.