diff --git a/metagpt/memory/brain_memory.py b/metagpt/memory/brain_memory.py
index b8f9a2a15..59d108a7d 100644
--- a/metagpt/memory/brain_memory.py
+++ b/metagpt/memory/brain_memory.py
@@ -156,7 +156,9 @@ class BrainMemory(pydantic.BaseModel):
             part_max_words = min(int(max_words / len(text_windows)) + 1, 100)
             summaries = []
             for ws in text_windows:
-                response = await self._get_summary(text=ws, max_words=part_max_words, keep_language=keep_language)
+                response = await self._get_summary(
+                    text=ws, llm=llm, max_words=part_max_words, keep_language=keep_language
+                )
                 summaries.append(response)
             if len(summaries) == 1:
                 summary = summaries[0]
diff --git a/metagpt/provider/openai_api.py b/metagpt/provider/openai_api.py
index 514671488..81be1975a 100644
--- a/metagpt/provider/openai_api.py
+++ b/metagpt/provider/openai_api.py
@@ -263,15 +263,6 @@ class OpenAIGPTAPI(BaseGPTAPI, RateLimiter):
         raise openai.error.OpenAIError("Exceeds the maximum retries")
 
     async def get_summary(self, text: str, max_words=200, keep_language: bool = False, **kwargs) -> str:
-        """
-        Return string in the following format：
-        [
-            {"role": "system", "content": "You are a helpful assistant."},
-            {"role": "user", "content": "Knock knock."},
-            {"role": "assistant", "content": "Who's there?"},
-            {"role": "user", "content": "Orange."},
-        ]
-        """
         from metagpt.memory.brain_memory import BrainMemory
 
         memory = BrainMemory(llm_type=LLMType.OPENAI.value, historical_summary=text, cacheable=False)