Add final answer

agent.py

@@ -61,15 +61,48 @@ def youtube_analysis_tool(question: str, url: str) -> str | None:
         raise RuntimeError(f"Processing failed: {str(e)}") from e
 
 class BasicAgent:
+    def _generate_final_answer(self, question: str, answer: str) -> str:
+        prompt = f"""
+        **Question:** {question}
+        
+        **Initial answer:** {answer}
+        
+        **Example 1:** What is the biggest city in California? Los Angeles
+        **Example 2:** How many 'r's are in strawberry? 3
+        **Example 3:** What is the opposite of black? White
+        **Example 4:** What are the first 5 numbers in the Fibonacci sequence? 0, 1, 1, 2, 3
+        **Example 5:** What is the opposite of bad, worse, worst? good, better, best
+        
+        **Final answer:** 
+        """
+        return self.final_answer_agent.run_sync(prompt).output
+
     def __init__(self):
         self.agent = Agent(
             "gemini-2.5-flash-preview-05-20",
             tools=[web_search_tool, youtube_analysis_tool],
             system_prompt="You are a helpful assistant that can answer questions about the world.",
         )
+        self.final_answer_agent = Agent(
+            "gemini-2.5-flash-preview-05-20",
+            system_prompt="""
+        You are an expert question answering assistant. Given a question and an initial answer, your task is to provide the final answer.
+        Your final answer must be a number and/or string 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 USD, $, percent, or % unless specified otherwise.
+        If you are asked for a string, don't use articles, neither abbreviations (for example 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.
+        If the final answer is a number, use a number not a word.
+        If the final answer is a string, start with an uppercase character.
+        If the final answer is a comma-separated list of numbers, use a space character after each comma.
+        If the final answer is a comma-separated list of strings, use a space character after each comma and start with a lowercase character.
+        Do not add any content to the final answer that is not in the initial answer.
+        """,
+        )
 
     def __call__(self, question: str) -> str:
         print(f"Agent received question (first 50 chars): {question[:50]}...")
         result = self.agent.run_sync(question).output
-        print(f"Agent returning fixed answer: {result}")
-        return result
+        print(f"Agent returning initial answer: {result}")
+        final_answer = self._generate_final_answer(question, result)
+        print(f"Agent returning final answer: {final_answer}")
+        return final_answer