WordPress at a glance
filter is not described

get_the_post_type_description filter-hook . WP 4.9.0

Filters the description for a post type archive.

Usage

add_filter( 'get_the_post_type_description', 'filter_function_name_2012', 10, 2 );
function filter_function_name_2012( $description, $post_type_obj ){
	// filter...

	return $description;
}
$description(string)
The post type description.
$post_type_obj(WP_Post_Type)
The post type object.

Where the hook is called

get_the_post_type_description()
wp-includes/general-template.php 1603
return apply_filters( 'get_the_post_type_description', $description, $post_type_obj );

Where the hook is used (in WP core)

wp-includes/default-filters.php 141
add_filter( $filter, 'wptexturize' );
wp-includes/default-filters.php 142
add_filter( $filter, 'convert_chars' );
wp-includes/default-filters.php 143
add_filter( $filter, 'wpautop' );
wp-includes/default-filters.php 144
add_filter( $filter, 'shortcode_unautop');