I have this shortcode function:

function category_description_output($atts) {
  $atts = shortcode_atts( array(
    'catID' => '16'
  ), $atts, 'categorydescription' );

  return category_description( $atts['catID'] );
}
add_shortcode('categorydescription', 'category_description_output');

My shortcodes look like this:
[categorydescription catID=16]
[categorydescription catID=17]
[categorydescription catID=18]
[categorydescription catID=19]

But they are all outputing the category description for the default ID of 16.