Don't pass the whole state, pass only messages instead

app.py

@@ -86,8 +86,12 @@ class BasicAgent:
             content=f"""You are a general AI assistant. I will ask you a question. Report your thoughts, and finish your answer with the following template: FINAL ANSWER: [YOUR FINAL ANSWER]. YOUR FINAL ANSWER should be a number OR as few words as possible OR a comma separated list of numbers and/or strings. If you are asked for a number, don't use comma to write your number neither use units such as $ or percent sign unless specified otherwise. If you are asked for a string, don't use articles, neither abbreviations (e.g. for cities), and write the digits in plain text unless specified otherwise. If you are asked for a comma separated list, apply the above rules depending of whether the element to be put in the list is a number or a string. 
             You can use provided tools:\n{textual_description_of_tool}"""
         )
-        new_message = self.model_with_tools.invoke([sys_msg] + messages)
-        return add_messages(state, [new_message])
+        new_msg = self.model_with_tools.invoke([sys_msg] + messages)
+        new_messages = add_messages(messages, [new_msg])
+        return {
+            "question": state["question"],
+            "messages": new_messages,
+        }
 
     def search_tool(self, question: str, max_length: int = 1024) -> str:
         """