Use UpdateRole instead.
Modifies only the description of a role. This operation performs the same function as the Description parameter in the UpdateRole operation.
get/#Action=UpdateRoleDescription
Query parameters
RoleNamestring required
The name of the role that you want to modify.
Descriptionstring required
The new description that you want to apply to the specified role.
Action'UpdateRoleDescription' required
Version'2010-05-08' required
Response
Success