diff --git a/metagpt/exp_pool/serializers/role_zero.py b/metagpt/exp_pool/serializers/role_zero.py
index 7876ef12a..82a32e36b 100644
--- a/metagpt/exp_pool/serializers/role_zero.py
+++ b/metagpt/exp_pool/serializers/role_zero.py
@@ -11,8 +11,7 @@ class RoleZeroSerializer(SimpleSerializer):
     def serialize_req(self, req: list[dict]) -> str:
         """Serialize the request for database storage, ensuring it is a string.
 
-        This function modifies the content of the last element in the request to remove unnecessary sections,
-        making the request more concise.
+        This function does not modify `req`; it only extracts the necessary content from `req` because `req` may be very lengthy and could cause embedding errors.
 
         Args:
             req (list[dict]): The request to be serialized. Example:
@@ -28,8 +27,33 @@ class RoleZeroSerializer(SimpleSerializer):
         if not req:
             return ""
 
-        req_copy = copy.deepcopy(req)
-        last_content = req_copy[-1]["content"]
+        filtered_req = self._filter_req(req)
+        self._clean_last_entry_content(filtered_req)
+
+        return json.dumps(filtered_req)
+
+    def _filter_req(self, req: list[dict]) -> list[dict]:
+        """Filter the request to include only necessary items and the last entry.
+
+        Args:
+            req (list[dict]): The original request.
+
+        Returns:
+            list[dict]: The filtered request.
+        """
+
+        filtered_req = [
+            copy.deepcopy(item) for item in req if "Command Editor.read executed: file_path" in item["content"]
+        ]
+        filtered_req.append(copy.deepcopy(req[-1]))
+
+        return filtered_req
+
+    def _clean_last_entry_content(self, req: list[dict]):
+        """Modifies the content of the last element in the request to remove unnecessary sections, making the request more concise."""
+
+        last_content = req[-1]["content"]
+
         last_content = RoleZeroContextBuilder.replace_content_between_markers(
             last_content, "# Data Structure", "# Current Plan", ""
         )
@@ -37,6 +61,4 @@ class RoleZeroSerializer(SimpleSerializer):
             last_content, "# Example", "# Instruction", ""
         )
 
-        req_copy[-1]["content"] = last_content
-
-        return json.dumps(req_copy)
+        req[-1]["content"] = last_content