diff --git a/base_telegram_inference_bot.py b/base_telegram_inference_bot.py
index 2033474..a9b7b52 100644
--- a/base_telegram_inference_bot.py
+++ b/base_telegram_inference_bot.py
@@ -14,8 +14,12 @@ class BaseTelegramInferenceBot(ABC):
 
     @staticmethod
     def load_system_prompt():
-        with open(os.environ.get("SYSTEM_PROMPT_PATH"), "r", encoding="utf-8") as file:
-            return file.read().strip()
+        system_prompt_path = os.getenv("SYSTEM_PROMPT_PATH")
+        if system_prompt_path and os.path.isfile(system_prompt_path):
+            with open(system_prompt_path, "r", encoding="utf-8") as file:
+                return file.read().strip()
+        else:
+            raise FileNotFoundError("SYSTEM_PROMPT_PATH is not set or file does not exist.")
 
     @staticmethod
     def load_functions():
@@ -52,7 +56,7 @@ class BaseTelegramInferenceBot(ABC):
 
     def call_tool(self, function_call_name, function_call_arguments):
         function_name = function_call_name
-        function_args = json.loads(function_call_arguments if function_call_arguments is not None else "{}")
+        function_args = json.loads(function_call_arguments if function_call_arguments is not None else "{}").
         for tool in self.tools:
             if function_name in [f["name"] for f in tool.get_functions()]:
                 return tool.execute(function_name, **function_args)