diff --git a/config.toml.example b/config.toml.example
index c4227dc6..04d64a40 100644
--- a/config.toml.example
+++ b/config.toml.example
@@ -1,5 +1,6 @@
 [discord]
 bot_token = "${DISCORD_BOT_TOKEN}"
+# Required: at least one channel ID. Empty list = bot will not respond to any messages.
 allowed_channels = ["1234567890"]
 
 [agent]
diff --git a/src/discord.rs b/src/discord.rs
index 8cb60e15..e7ea8f30 100644
--- a/src/discord.rs
+++ b/src/discord.rs
@@ -28,8 +28,7 @@ impl EventHandler for Handler {
         let bot_id = ctx.cache.current_user().id;
 
         let channel_id = msg.channel_id.get();
-        let in_allowed_channel =
-            self.allowed_channels.is_empty() || self.allowed_channels.contains(&channel_id);
+        let in_allowed_channel = self.allowed_channels.contains(&channel_id);
 
         let is_mentioned = msg.mentions_user_id(bot_id)
             || msg.content.contains(&format!("<@{}>", bot_id))
@@ -172,6 +171,9 @@ impl EventHandler for Handler {
 
     async fn ready(&self, _ctx: Context, ready: Ready) {
         info!(user = %ready.user.name, "discord bot connected");
+        if self.allowed_channels.is_empty() {
+            tracing::warn!("allowed_channels is empty — bot will NOT respond to any messages. Configure allowed_channels in config.toml.");
+        }
     }
 }