diff --git a/src/test/function_test/bulk_load/test_bulk_load.cpp b/src/test/function_test/bulk_load/test_bulk_load.cpp
index 3e1c7b3f47..ad791cf72e 100644
--- a/src/test/function_test/bulk_load/test_bulk_load.cpp
+++ b/src/test/function_test/bulk_load/test_bulk_load.cpp
@@ -41,6 +41,7 @@
 #include "common/bulk_load_common.h"
 #include "common/json_helper.h"
 #include "gtest/gtest.h"
+#include "include/pegasus/client.h" // IWYU pragma: keep
 #include "meta/meta_bulk_load_service.h"
 #include "metadata_types.h"
 #include "test/function_test/utils/global_env.h"
diff --git a/src/test/function_test/utils/test_util.cpp b/src/test/function_test/utils/test_util.cpp
index 857d7148a8..a395b4b3c2 100644
--- a/src/test/function_test/utils/test_util.cpp
+++ b/src/test/function_test/utils/test_util.cpp
@@ -66,7 +66,7 @@ test_util::test_util(map<string, string> create_envs)
     : kOpNames({{test_util::OperateDataType::kSet, "set"},
                 {test_util::OperateDataType::kGet, "get"},
                 {test_util::OperateDataType::kDelete, "delete"},
-                {test_util::OperateDataType::kCheckNotFound, "check data not found"}}),
+                {test_util::OperateDataType::kCheckNotFound, "check not found"}}),
       kClusterName_("onebox"),
       kDefaultHashkeyPrefix("hashkey_"),
       kDefaultSortkey("sortkey"),
@@ -188,6 +188,8 @@ void test_util::operate_data(OperateDataType type,
     auto *client = pegasus_client_factory::get_client(kClusterName_.c_str(), table_name.c_str());
     ASSERT_NE(client, nullptr);
     int64_t start = dsn_now_ms();
+    ASSERT_GT(count, 0);
+    ASSERT_LT(count, 10000);
     for (int i = 0; i < count; i++) {
         auto hashkey = fmt::format("{}{:04}", hashkey_prefix, i);
         std::string value;
diff --git a/src/test/function_test/utils/test_util.h b/src/test/function_test/utils/test_util.h
index 885775f790..a2444b4dfc 100644
--- a/src/test/function_test/utils/test_util.h
+++ b/src/test/function_test/utils/test_util.h
@@ -66,10 +66,12 @@ class test_util : public ::testing::Test
 
     void wait_table_healthy(const std::string &table_name) const;
 
+    // Write some data to table 'table_name_' according to the parameters.
     void
     write_data(const std::string &hashkey_prefix, const std::string &value_prefix, int count) const;
     void write_data(int count) const;
 
+    // Verify the data can be read from the table according to the parameters.
     void verify_data(const std::string &table_name,
                      const std::string &hashkey_prefix,
                      const std::string &value_prefix,
@@ -77,9 +79,11 @@ class test_util : public ::testing::Test
     void verify_data(int count) const;
     void verify_data(const std::string &table_name, int count) const;
 
+    // Delete some data from the table according to the parameters.
     void
     delete_data(const std::string &table_name, const std::string &hashkey_prefix, int count) const;
 
+    // Verify the data can NOT be read from the table according to the parameters.
     void check_not_found(const std::string &table_name,
                          const std::string &hashkey_prefix,
                          int count) const;