Try to use tool decorator instead of duplicating function docstring and tool doc logic

app.py

@@ -16,6 +16,7 @@ from langgraph.prebuilt import ToolNode, tools_condition
 from langchain_openai import ChatOpenAI
 # from langchain_community.tools import DuckDuckGoSearchRun
 from langchain_core.messages import SystemMessage, HumanMessage, AnyMessage
+from langchain_core.tools import tool
 
 
 # --- Constants ---
@@ -49,17 +50,17 @@ class BasicAgent:
     def __call__(self, question: str) -> Tuple[str, List[Dict[str, Any]]]:
         print(f"Agent received question: {question}")
 
-        tool_doc = """
-        search_tool(question: str, max_length: int = 2048) -> str:
-            Search info on the web.
-        Args:
-            question: Question string
-            max_length: maximum characters in the output
-        Returns:
-            A single string containing the info from the web or a fallback message.
-        """
+        # tool_doc = """
+        # search_tool(question: str, max_length: int = 2048) -> str:
+        #     Search info on the web.
+        # Args:
+        #     question: Question string
+        #     max_length: maximum characters in the output
+        # Returns:
+        #     A single string containing the info from the web or a fallback message.
+        # """
         sys_msg = SystemMessage(
-            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. You can use provided tools:\n{tool_doc}"""
+            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."""
         )
             
         state = State(
@@ -81,16 +82,11 @@ class BasicAgent:
             "messages": [response]
         }
 
+    @tool(
+      name="search_tool",
+      description="Search the web using DuckDuckGo and return the best result snippet.",
+    )
     def search_tool(self, question: str, max_length: int = 2048) -> str:
-        """
-        Use DuckDuckGo’s API to fetch a direct answer.
-        
-        Args:
-            question: The question to ask.
-            max_length: Max chars to return.
-        Returns:
-            Answer text, or a fallback message.
-        """
         print(f"Calling search tool with: {question}, max_lentgh: {max_length}")
         with DDGS() as ddgs:
             hits = list(ddgs.text(question, max_results=5))