diff --git a/OpenRA.Mods.Common/Traits/Player/EnemyWatcher.cs b/OpenRA.Mods.Common/Traits/Player/EnemyWatcher.cs
index 6bd49a22ea..7875e99c54 100644
--- a/OpenRA.Mods.Common/Traits/Player/EnemyWatcher.cs
+++ b/OpenRA.Mods.Common/Traits/Player/EnemyWatcher.cs
@@ -16,7 +16,7 @@ using OpenRA.Traits;
 namespace OpenRA.Mods.Common.Traits
 {
 	[Desc("Tracks neutral and enemy actors' visibility and notifies the player.",
-		"Attach this to the player actor.")]
+		"Attach this to the player actor. The actors to track need the 'AnnounceOnSeen' trait.")]
 	class EnemyWatcherInfo : ITraitInfo
 	{
 		[Desc("Interval in ticks between scanning for enemies.")]
diff --git a/OpenRA.Mods.Common/Traits/Sound/AnnounceOnSeen.cs b/OpenRA.Mods.Common/Traits/Sound/AnnounceOnSeen.cs
index afcb49f620..565f3c464a 100644
--- a/OpenRA.Mods.Common/Traits/Sound/AnnounceOnSeen.cs
+++ b/OpenRA.Mods.Common/Traits/Sound/AnnounceOnSeen.cs
@@ -15,7 +15,8 @@ using OpenRA.Traits;
 
 namespace OpenRA.Mods.Common.Traits.Sound
 {
-	[Desc("Players will be notified when this actor becomes visible to them.")]
+	[Desc("Players will be notified when this actor becomes visible to them.",
+		"Requires the 'EnemyWatcher' trait on the player actor.")]
 	public class AnnounceOnSeenInfo : ITraitInfo
 	{
 		[Desc("Should there be a radar ping on enemies' radar at the actor's location when they see him")]