refactor -- following guidelines to push tools

tool.py

@@ -1,3 +1,5 @@
+import os
+
 from dataclasses import dataclass
 from typing import List, Optional, Tuple
 
@@ -154,6 +156,7 @@ class VisualRAGTool(Tool):
     output_type = "string"
 
     model_name: str = "vidore/colqwen2-v1.0"
+    api_key: str = os.getenv("OPENAI_KEY")
 
     def _init_models(self, model_name: str) -> None:
         self.device = "cuda" if torch.cuda.is_available() else "cpu"