Improve active skill schema handling

agent/ai_service_failure_test.go

@@ -29,3 +29,26 @@ func TestAIServiceFailureHighlightsHTMLGatewayResponse(t *testing.T) {
 		t.Fatalf("html parse error should not use the generic balance/timeout-only guidance: %s", msg)
 	}
 }
+
+func TestAIServiceFailureHighlightsUpstreamEmptyOutputRateLimit(t *testing.T) {
+	a := New(nil, nil, DefaultConfig(), slog.Default())
+
+	msg, err := a.aiServiceFailure("zh", errors.New(`API returned error (status 429): {"error":{"code":"upstream_empty_output","message":"Upstream model returned empty output.","param":null,"type":"rate_limit_error"}}`))
+	if err != nil {
+		t.Fatalf("aiServiceFailure returned error: %v", err)
+	}
+
+	for _, want := range []string{
+		"当前 AI 服务调用失败",
+		"上游模型没有返回有效内容",
+		"不应优先归因成“余额不足”",
+		"切换到另一个可用模型",
+	} {
+		if !strings.Contains(msg, want) {
+			t.Fatalf("expected message to contain %q, got: %s", want, msg)
+		}
+	}
+	if strings.Contains(msg, "更可能是模型服务余额不足、接口报错、鉴权失败或超时") {
+		t.Fatalf("upstream empty output should not use the generic balance/auth/timeout guidance: %s", msg)
+	}
+}