WordPress at a glance
filter is not described

post_comments_link filter-hook . WP 2.7.0

Filters the formatted post comments link HTML.

Usage

add_filter( 'post_comments_link', 'filter_function_name_2606', 10, 2 );
function filter_function_name_2606( $formatted, $post ){
	// filter...

	return $formatted;
}
$formatted(string)
The HTML-formatted post comments link.
$post(int/WP_Post)
The post ID or WP_Post object.

Where the hook is called

get_post_reply_link()
wp-includes/comment-template.php 1760
return apply_filters( 'post_comments_link', $formatted_link, $post );

Where the hook is used (in WP core)

Does not used.