API: problem sorting contacts on ID

I wanted to retrieve the most recently added contacts using the API. I did it like this:

$result = civicrm_api3('Contact', 'get', array(
'sequential' => 1,
'options' => array('sort' => "id DESC"),
));

I got an error message, because id was ambiguous. It seems I could work around the problem this way:

$result = civicrm_api3('Contact', 'get', array(
'sequential' => 1,
'options' => array('sort' => "contact_a.id DESC"),
));

But I think it would be better if an unqualified sort field would be applied to the entity that is retrieved.