diff --git a/examples/debate.py b/examples/debate.py
index 630f78cd8..597b44e8d 100644
--- a/examples/debate.py
+++ b/examples/debate.py
@@ -15,6 +15,7 @@ from metagpt.logs import logger
 from metagpt.roles import Role
 from metagpt.schema import Message
 from metagpt.software_company import SoftwareCompany
+from metagpt.utils.common import any_to_str
 
 
 class ShoutOut(Action):
@@ -101,7 +102,9 @@ class Biden(Role):
         await super()._observe()
         # accept the very first human instruction (the debate topic) or messages sent (from opponent) to self,
         # disregard own messages from the last round
-        self._rc.news = [msg for msg in self._rc.news if msg.cause_by == BossRequirement or msg.send_to == {self.name}]
+        self._rc.news = [
+            msg for msg in self._rc.news if msg.cause_by == any_to_str(BossRequirement) or msg.send_to == {self.name}
+        ]
         return len(self._rc.news)
 
     async def _act(self) -> Message:
diff --git a/metagpt/roles/engineer.py b/metagpt/roles/engineer.py
index 960f9c0f3..535a1e27f 100644
--- a/metagpt/roles/engineer.py
+++ b/metagpt/roles/engineer.py
@@ -141,13 +141,13 @@ class Engineer(Role):
             logger.info(todo)
             logger.info(code_rsp)
             # self.write_file(todo, code)
-            msg = Message(content=code_rsp, role=self.profile, cause_by=any_to_str(self._rc.todo))
+            msg = Message(content=code_rsp, role=self.profile, cause_by=self._rc.todo)
             self._rc.memory.add(msg)
             self.publish_message(msg)
             del self.todos[0]
 
         logger.info(f"Done {self.get_workspace()} generating.")
-        msg = Message(content="all done.", role=self.profile, cause_by=any_to_str(self._rc.todo))
+        msg = Message(content="all done.", role=self.profile, cause_by=self._rc.todo)
         return msg
 
     async def _act_sp(self) -> Message:
@@ -158,7 +158,7 @@ class Engineer(Role):
             # logger.info(code_rsp)
             # code = self.parse_code(code_rsp)
             file_path = self.write_file(todo, code)
-            msg = Message(content=code, role=self.profile, cause_by=any_to_str(self._rc.todo))
+            msg = Message(content=code, role=self.profile, cause_by=self._rc.todo)
             self._rc.memory.add(msg)
             self.publish_message(msg)
 
@@ -169,7 +169,7 @@ class Engineer(Role):
         msg = Message(
             content=MSG_SEP.join(code_msg_all),
             role=self.profile,
-            cause_by=any_to_str(self._rc.todo),
+            cause_by=self._rc.todo,
             send_to="Edward",
         )
         return msg
@@ -211,7 +211,7 @@ class Engineer(Role):
         msg = Message(
             content=MSG_SEP.join(code_msg_all),
             role=self.profile,
-            cause_by=any_to_str(self._rc.todo),
+            cause_by=self._rc.todo,
             send_to="Edward",
         )
         return msg
diff --git a/metagpt/roles/qa_engineer.py b/metagpt/roles/qa_engineer.py
index 0f932ebfb..760b65736 100644
--- a/metagpt/roles/qa_engineer.py
+++ b/metagpt/roles/qa_engineer.py
@@ -22,7 +22,7 @@ from metagpt.const import WORKSPACE_ROOT
 from metagpt.logs import logger
 from metagpt.roles import Role
 from metagpt.schema import Message
-from metagpt.utils.common import CodeParser, any_to_str, any_to_str_set, parse_recipient
+from metagpt.utils.common import CodeParser, any_to_str_set, parse_recipient
 from metagpt.utils.special_tokens import FILENAME_CODE_SEP, MSG_SEP
 
 
@@ -99,7 +99,7 @@ class QaEngineer(Role):
             msg = Message(
                 content=str(file_info),
                 role=self.profile,
-                cause_by=any_to_str(WriteTest),
+                cause_by=WriteTest,
                 sent_from=self.profile,
                 send_to=self.profile,
             )
@@ -133,9 +133,7 @@ class QaEngineer(Role):
 
         recipient = parse_recipient(result_msg)  # the recipient might be Engineer or myself
         content = str(file_info) + FILENAME_CODE_SEP + result_msg
-        msg = Message(
-            content=content, role=self.profile, cause_by=any_to_str(RunCode), sent_from=self.profile, send_to=recipient
-        )
+        msg = Message(content=content, role=self.profile, cause_by=RunCode, sent_from=self.profile, send_to=recipient)
         self.publish_message(msg)
 
     async def _debug_error(self, msg):
@@ -147,7 +145,7 @@ class QaEngineer(Role):
             msg = Message(
                 content=file_info,
                 role=self.profile,
-                cause_by=any_to_str(DebugError),
+                cause_by=DebugError,
                 sent_from=self.profile,
                 send_to=recipient,
             )
@@ -165,7 +163,7 @@ class QaEngineer(Role):
             result_msg = Message(
                 content=f"Exceeding {self.test_round_allowed} rounds of tests, skip (writing code counts as a round, too)",
                 role=self.profile,
-                cause_by=any_to_str(WriteTest),
+                cause_by=WriteTest,
                 sent_from=self.profile,
             )
             return result_msg
@@ -189,7 +187,7 @@ class QaEngineer(Role):
         result_msg = Message(
             content=f"Round {self.test_round} of tests done",
             role=self.profile,
-            cause_by=any_to_str(WriteTest),
+            cause_by=WriteTest,
             sent_from=self.profile,
         )
         return result_msg
diff --git a/metagpt/roles/researcher.py b/metagpt/roles/researcher.py
index 8d5e43fab..29889b8ec 100644
--- a/metagpt/roles/researcher.py
+++ b/metagpt/roles/researcher.py
@@ -15,7 +15,6 @@ from metagpt.const import RESEARCH_PATH
 from metagpt.logs import logger
 from metagpt.roles import Role
 from metagpt.schema import Message
-from metagpt.utils.common import any_to_str
 
 
 class Report(BaseModel):
@@ -64,20 +63,18 @@ class Researcher(Role):
         research_system_text = get_research_system_text(topic, self.language)
         if isinstance(todo, CollectLinks):
             links = await todo.run(topic, 4, 4)
-            ret = Message("", Report(topic=topic, links=links), role=self.profile, cause_by=any_to_str(todo))
+            ret = Message("", Report(topic=topic, links=links), role=self.profile, cause_by=todo)
         elif isinstance(todo, WebBrowseAndSummarize):
             links = instruct_content.links
             todos = (todo.run(*url, query=query, system_text=research_system_text) for (query, url) in links.items())
             summaries = await asyncio.gather(*todos)
             summaries = list((url, summary) for i in summaries for (url, summary) in i.items() if summary)
-            ret = Message("", Report(topic=topic, summaries=summaries), role=self.profile, cause_by=any_to_str(todo))
+            ret = Message("", Report(topic=topic, summaries=summaries), role=self.profile, cause_by=todo)
         else:
             summaries = instruct_content.summaries
             summary_text = "\n---\n".join(f"url: {url}\nsummary: {summary}" for (url, summary) in summaries)
             content = await self._rc.todo.run(topic, summary_text, system_text=research_system_text)
-            ret = Message(
-                "", Report(topic=topic, content=content), role=self.profile, cause_by=any_to_str(self._rc.todo)
-            )
+            ret = Message("", Report(topic=topic, content=content), role=self.profile, cause_by=self._rc.todo)
         self._rc.memory.add(ret)
         return ret
 
diff --git a/metagpt/roles/role.py b/metagpt/roles/role.py
index ccad0b018..5c512b0f0 100644
--- a/metagpt/roles/role.py
+++ b/metagpt/roles/role.py
@@ -210,10 +210,10 @@ class Role:
                 content=response.content,
                 instruct_content=response.instruct_content,
                 role=self.profile,
-                cause_by=any_to_str(self._rc.todo),
+                cause_by=self._rc.todo,
             )
         else:
-            msg = Message(content=response, role=self.profile, cause_by=any_to_str(self._rc.todo))
+            msg = Message(content=response, role=self.profile, cause_by=self._rc.todo)
 
         return msg
 
diff --git a/metagpt/roles/seacher.py b/metagpt/roles/seacher.py
index a37143196..587698d1d 100644
--- a/metagpt/roles/seacher.py
+++ b/metagpt/roles/seacher.py
@@ -12,7 +12,6 @@ from metagpt.logs import logger
 from metagpt.roles import Role
 from metagpt.schema import Message
 from metagpt.tools import SearchEngineType
-from metagpt.utils.common import any_to_str
 
 
 class Searcher(Role):
@@ -64,10 +63,10 @@ class Searcher(Role):
                 content=response.content,
                 instruct_content=response.instruct_content,
                 role=self.profile,
-                cause_by=any_to_str(self._rc.todo),
+                cause_by=self._rc.todo,
             )
         else:
-            msg = Message(content=response, role=self.profile, cause_by=any_to_str(self._rc.todo))
+            msg = Message(content=response, role=self.profile, cause_by=self._rc.todo)
         self._rc.memory.add(msg)
         return msg