How to rename docname when save

Hello !
I am trying to rename docname when a field value is changed for that i wrote code :

    def validate(self):	
		if self.description != self.name :
			frappe.rename_doc("Brand", self.name, self.description)

it is rename the docname but not update the link at the time i have to manually change the url and even not store the updated description as well any idea on this ?