diff --git a/cmd/roles/healthz_handler.go b/cmd/roles/healthz_handler.go
index d025e5c05d..0ba4b1ee4c 100644
--- a/cmd/roles/healthz_handler.go
+++ b/cmd/roles/healthz_handler.go
@@ -46,7 +46,9 @@ func healthyHandler(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// GetComponentStatesInterface defines the interface that get states from component.
 type GetComponentStatesInterface interface {
+	// GetComponentStates returns the states of component.
 	GetComponentStates(ctx context.Context, request *internalpb.GetComponentStatesRequest) (*internalpb.ComponentStates, error)
 }