diff --git a/system-variables.md b/system-variables.md
index a26d5fd05f37c..5122cfb03b933 100644
--- a/system-variables.md
+++ b/system-variables.md
@@ -4621,7 +4621,7 @@ SHOW WARNINGS;
 ### tidb_read_consistency <span class="version-mark">New in v5.4.0</span>
 
 - Scope: SESSION
-- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): Yes
+- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): Yes (Note that if [non-transactional DML statements](/non-transactional-dml.md) exist, modifying the value of this variable using hint might not take effect.)
 - Type: String
 - Default value: `strict`
 - This variable is used to control the read consistency for an auto-commit read statement.
@@ -4631,7 +4631,7 @@ SHOW WARNINGS;
 ### tidb_read_staleness <span class="version-mark">New in v5.4.0</span>
 
 - Scope: SESSION
-- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): Yes
+- Applies to hint [SET_VAR](/optimizer-hints.md#set_varvar_namevar_value): No
 - Type: Integer
 - Default value: `0`
 - Range: `[-2147483648, 0]`