diff --git a/ocr/app/engines/gemini_engine.py b/ocr/app/engines/gemini_engine.py
index 5a1a61b..b26a3c0 100644
--- a/ocr/app/engines/gemini_engine.py
+++ b/ocr/app/engines/gemini_engine.py
@@ -148,13 +148,15 @@ class GeminiEngine:
             return self._model
 
         except ImportError as exc:
+            logger.exception("Vertex AI SDK import failed")
             raise GeminiUnavailableError(
                 "google-cloud-aiplatform is not installed. "
                 "Install with: pip install google-cloud-aiplatform"
             ) from exc
         except Exception as exc:
+            logger.exception("Vertex AI authentication failed")
             raise GeminiUnavailableError(
-                f"Failed to initialize Gemini engine: {exc}"
+                f"Vertex AI authentication failed: {exc}"
             ) from exc
 
     def extract_maintenance(