prompt fix

gemini_agent.py

@@ -639,7 +639,9 @@ When you have the final answer, you MUST use exactly one line with this format (
 Thought: Do I need to use a tool? No
 Final Answer: [your response here]
 
-Begin! Remember to ALWAYS include 'Thought:', 'Action:', 'Action Input:', and 'Final Answer:' in your responses."""
+IMPORTANT: Every output MUST start with 'Thought:' and follow the above format exactly. Do NOT omit 'Thought:' at the beginning.
+Begin! 
+"""
 
         SUFFIX = """Previous conversation history:
 {chat_history}