diff --git a/skills/lark-im/SKILL.md b/skills/lark-im/SKILL.md
index 7ec3b7118..a7381ee37 100644
--- a/skills/lark-im/SKILL.md
+++ b/skills/lark-im/SKILL.md
@@ -55,6 +55,10 @@ The four message-pulling shortcuts (`+messages-mget`, `+chat-messages-list`, `+m
 
 Card messages (`interactive` type) are not yet supported for compact conversion in event subscriptions. The raw event data will be returned instead, with a hint printed to stderr.
 
+### Audio Messages
+
+`--audio` supports only Opus audio files when sending or replying with audio messages, for example `.opus` files or Ogg Opus (`.ogg`) files.
+
 ### Flag Types
 
 Flags support two layers: