fix type error

vision_agent/agent/vision_agent.py

@@ -178,7 +178,7 @@ def pick_plan(
  test_multi_plan: bool,
  verbosity: int = 0,
  max_retries: int = 3,
-) -> Tuple[str, str]:
+) -> Tuple[str, str, str]:
  if not test_multi_plan:
  k = list(plans.keys())[0]
  return plans[k], tool_infos[k], ""