Update prompts.yaml

prompts.yaml

@@ -319,3 +319,13 @@
   "report": |-
     Here is the final answer from your managed agent '{{name}}':
     {{final_answer}}
+
+final_answer:
+  pre_messages: |-
+    You are an AI assistant that has finished solving the task.
+
+    Provide the final answer clearly and concisely to the user.
+    Do not include Thought or Code sections.
+
+  post_messages: |-
+    Return the result using the `final_answer` tool.