diff --git a/database/main.py b/database/main.py
index d55ee95..a694ec4 100644
--- a/database/main.py
+++ b/database/main.py
@@ -34,8 +34,11 @@ def create_token():
     refresh_token = data.get('refresh_token')
     expiration_seconds = data.get('expiration_seconds')
 
-    if not email or access_token or not refresh_token or not expiration_seconds:
-        return 'Missing required fields', 400
+    required_fields = ['email', 'access_token', 'refresh_token', 'expiration_seconds']
+    missing_fields = [field for field in required_fields if not data.get(field)]
+
+    if missing_fields:
+        return jsonify({'error': f'Missing required fields: {", ".join(missing_fields)}'}), 400
 
     # unique email when active is true
     existing_token = Token.query.filter_by(email=email, active=True).first()