Update app.py

Add docstrinfg to count_letter_in_word

app.py

@@ -20,6 +20,11 @@ def my_custom_tool(arg1:str, arg2:int)-> str: #it's import to specify the return
 
 @tool
 def count_letter_in_word(word:str, letter:str)-> str: # Strawberry special
+    """A tool that count the number of time a given letter appears in a word 
+    Args:
+        word: A string representing the word in which we search the letter.
+        letter: A string representing the letter to search.
+    """
     count = 0
     for character in word:
         if character == letter: