diff --git a/metagpt/document_store/faiss_store.py b/metagpt/document_store/faiss_store.py
index 54585dcfc..2359917d5 100644
--- a/metagpt/document_store/faiss_store.py
+++ b/metagpt/document_store/faiss_store.py
@@ -37,11 +37,7 @@ class FaissStore(LocalStore):
         return FAISS.load_local(self.raw_data_path.parent, self.embedding, self.fname)
 
     def _write(self, docs, metadatas):
-        try:
-            store = FAISS.from_texts(docs, self.embedding, metadatas=metadatas)
-        except Exception as e:
-            logger.error(f"Failed to write. error: {e}")
-            raise e
+        store = FAISS.from_texts(docs, self.embedding, metadatas=metadatas)
         return store
 
     def persist(self):
diff --git a/metagpt/roles/role.py b/metagpt/roles/role.py
index ef71bbd96..5da39f80f 100644
--- a/metagpt/roles/role.py
+++ b/metagpt/roles/role.py
@@ -523,20 +523,29 @@ class Role(SerializationMixin, ContextMixin, BaseModel):
         return not self.rc.news and not self.rc.todo and self.rc.msg_buffer.empty()
 
     async def think(self) -> Action:
-        """The exported `think` function"""
-        await self._observe()
+        """
+        Export SDK API, used by AgentStore RPC.
+        The exported `think` function
+        """
+        await self._observe()  # For compatibility with the old version of the Agent.
         await self._think()
         return self.rc.todo
 
     async def act(self) -> ActionOutput:
-        """The exported `act` function"""
+        """
+        Export SDK API, used by AgentStore RPC.
+        The exported `act` function
+        """
         msg = await self._act()
         return ActionOutput(content=msg.content, instruct_content=msg.instruct_content)
 
     @property
     def action_description(self) -> str:
         """
+        Export SDK API, used by AgentStore RPC and Agent.
         AgentStore uses this attribute to display to the user what actions the current role should take.
+        `Role` provides the default property, and this property should be overridden by children classes if necessary,
+        as demonstrated by the `Engineer` class.
         """
         if self.rc.todo:
             if self.rc.todo.desc: