diff --git a/agent.py b/agent.py
index 92175c7..40ec562 100644
--- a/agent.py
+++ b/agent.py
@@ -318,6 +318,10 @@ def _validate_comparison_request(
     return None
 
 
+def _rank_sort_key(row: dict[str, Any]) -> tuple[Any, ...]:
+    return (-row["score"], row["total_price"], row["delivery_days"], -row["warranty_months"], row["vendor"])
+
+
 def _score_quotes(comparison_id: str, quotes: list[QuoteInput], weights: QuoteWeights) -> dict[str, Any]:
     total_weight = Decimal(str(weights.price + weights.delivery + weights.warranty))
     prices = [_money(q.unit_price) for q in quotes]
@@ -351,7 +355,7 @@ def _score_quotes(comparison_id: str, quotes: list[QuoteInput], weights: QuoteWe
                 },
             }
         )
-    rows.sort(key=lambda item: (-item["score"], item["total_price"], item["delivery_days"], -item["warranty_months"], item["vendor"]))
+    rows.sort(key=_rank_sort_key)
     for rank, row in enumerate(rows, start=1):
         row["rank"] = rank
     recommendation = rows[0]