modify size of the description field in Media window

Hi there,

I am looking to increase the height of the text area corresponding of the description of an image. currently is seems like it set to 2 rows and I would like to increase it to 5 or more.

I found the description field was set in media.php:

'post_content' => array(
			'label'      => __('Description'),
			'value'      => $edit_post->post_content,
			'input'      => 'textarea'

I tried to add
'rows' => 10
'rows' => '10'
'height' => 10
'height' => '10'
'height' => '10px'

but none of these worked

please help !