diff --git a/lib/service/servicecfg/auth.go b/lib/service/servicecfg/auth.go
index 1749fa05b5350..5c56d18b117c1 100644
--- a/lib/service/servicecfg/auth.go
+++ b/lib/service/servicecfg/auth.go
@@ -254,7 +254,9 @@ type GCPKMSConfig struct {
 }
 
 const (
-	GCPKMSProtectionLevelHSM      = "HSM"
+	// GCPKMSProtectionLevelHSM represents the HSM protection level in GCP KMS.
+	GCPKMSProtectionLevelHSM = "HSM"
+	// GCPKMSProtectionLevelSoftware represents the SOFTWARE protection level in GCP KMS.
 	GCPKMSProtectionLevelSoftware = "SOFTWARE"
 )