diff --git a/OpenRA.Mods.Common/Scripting/Global/TriggerGlobal.cs b/OpenRA.Mods.Common/Scripting/Global/TriggerGlobal.cs
index 98c783a2ee..983c7a6108 100644
--- a/OpenRA.Mods.Common/Scripting/Global/TriggerGlobal.cs
+++ b/OpenRA.Mods.Common/Scripting/Global/TriggerGlobal.cs
@@ -442,7 +442,7 @@ namespace OpenRA.Mods.Common.Scripting
 
 		[Desc("Call a function when this actor is discovered by an enemy or a player with a Neutral stance. " +
 			"The callback function will be called as func(Actor discovered, Player discoverer). " +
-			"The player actor needs the 'EnemyWatcher' trait.")]
+			"The player actor needs the 'EnemyWatcher' trait. The actors to discover need the 'AnnounceOnSeen' trait.")]
 		public void OnDiscovered(Actor a, LuaFunction func)
 		{
 			GetScriptTriggers(a).RegisterCallback(Trigger.OnDiscovered, func, Context);
@@ -450,7 +450,7 @@ namespace OpenRA.Mods.Common.Scripting
 
 		[Desc("Call a function when this player is discovered by an enemy or neutral player. " +
 			"The callback function will be called as func(Player discovered, Player discoverer, Actor discoveredActor)." +
-			"The player actor needs the 'EnemyWatcher' trait.")]
+			"The player actor needs the 'EnemyWatcher' trait. The actors to discover need the 'AnnounceOnSeen' trait.")]
 		public void OnPlayerDiscovered(Player discovered, LuaFunction func)
 		{
 			GetScriptTriggers(discovered.PlayerActor).RegisterCallback(Trigger.OnPlayerDiscovered, func, Context);