Update tools/search_item_ctrl_f.py

tools/search_item_ctrl_f.py

@@ -12,7 +12,7 @@ class SearchItemCtrlFTool(Tool):
     """
     inputs = {
         'text': {'type': 'string', 'description': 'The text to search for'},
-        'nth_result': {'type': 'integer', 'description': 'Which occurrence to jump to (default: 1)'}
+        'nth_result': {'type': 'integer', 'description': 'Which occurrence to jump to (default: 1)', 'nullable': True}
     }
     output_type = "string"