diff --git a/tests/metagpt/memory/test_longterm_memory.py b/tests/metagpt/memory/test_longterm_memory.py
index c40d7ab9d..712402db1 100644
--- a/tests/metagpt/memory/test_longterm_memory.py
+++ b/tests/metagpt/memory/test_longterm_memory.py
@@ -2,7 +2,8 @@
 # -*- coding: utf-8 -*-
 """
 @Desc   : unittest of `metagpt/memory/longterm_memory.py`
-@Modified By: mashenquan, 2023-11-1. Standardize the usage of message filtering-related features.
+@Modified By: mashenquan, 2023-11-1. According to Chapter 2.2.1 and 2.2.2 of RFC 116, change the data type of
+        the `cause_by` value in the `Message` to a string to support the new message distribution feature.
 """
 
 from metagpt.actions import BossRequirement