diff --git a/internal/providers/helpers.go b/internal/providers/helpers.go
index 6b0d35d3..f10b6605 100644
--- a/internal/providers/helpers.go
+++ b/internal/providers/helpers.go
@@ -191,6 +191,7 @@ func BuildOpenAIBody(request *models.UnifiedRequest, messagesJSON []interface{},
 			}
 		}
 		body["tools"] = sanitizedTools
+		body["reasoning_effort"] = "none" // pontytail: OpenAI reasoning models reject tools + reasoning_effort
 	}
 	if request.ToolChoice != nil {
 		var toolChoice interface{}