add docstring

app.py

@@ -47,9 +47,12 @@ def get_population(country:str)-> str: #it's import to specify the return type
 
 @tool
 def get_weather(city:str) -> str:
+    """A tool that returns the population for a country 
+    Args:
+        city: a string representing the a city to find the weather for
+    """
     API_KEY = os.getenv("WAPI")
-    CITY = "New York"
-    URL = f"http://api.weatherapi.com/v1/current.json?key={API_KEY}&q={CITY}&aqi=no"
+    URL = f"http://api.weatherapi.com/v1/current.json?key={API_KEY}&q={city}&aqi=no"
     response = requests.get(URL)
     if response.status_code == 200:
         data = response.json()