diff --git a/pr_agent/algo/utils.py b/pr_agent/algo/utils.py
index dd010921..4bd6c631 100644
--- a/pr_agent/algo/utils.py
+++ b/pr_agent/algo/utils.py
@@ -708,7 +708,7 @@ def get_max_tokens(model):
     elif settings.config.custom_model_max_tokens > 0:
         max_tokens_model = settings.config.custom_model_max_tokens
     else:
-        raise Exception(f"MAX_TOKENS must be set for model {model} in ./pr_agent/algo/__init__.py, or set config.custom_model_max_tokens")
+        raise Exception(f"Ensure {model} is defined in MAX_TOKENS in ./pr_agent/algo/__init__.py or set a positive value for it in config.custom_model_max_tokens")
 
     if settings.config.max_model_tokens and settings.config.max_model_tokens > 0:
         max_tokens_model = min(settings.config.max_model_tokens, max_tokens_model)