diff --git a/api/apps/kb_app.py b/api/apps/kb_app.py
index f173b56a0..53e42303f 100644
--- a/api/apps/kb_app.py
+++ b/api/apps/kb_app.py
@@ -918,6 +918,6 @@ def check_embedding():
     }
     if summary["avg_cos_sim"] > 0.9:
         return get_json_result(data={"summary": summary, "results": results})
-    return get_json_result(code=RetCode.NOT_EFFECTIVE, message="failed", data={"summary": summary, "results": results})
+    return get_json_result(code=RetCode.NOT_EFFECTIVE, message="Embedding model switch failed: the average similarity between old and new vectors is below 0.9, indicating incompatible vector spaces.", data={"summary": summary, "results": results})