Should I use t() in a hook_menu's description? I have always used t() for hook_menus title and description like this:

$items['some-path'] = array(
    'title' =&gt; t('My Page Title'),
    'description' =&gt; t('This is a description about what my page is for'),
    'page callback' =&gt; 'profile_user_page',
);


This makes sense to me so users can translate the title and description into different languages if required.

However this comment on a module review on DO says:

No, that's wrong, don't do that - descriptions in hook_menu() should never use t().

What is the reasoning for this and is this actually best practice?

Also if this is true then should we not use t() for the title as well?
See Strings at well-known places: built-in menus, permissions, log messages and .info files community documentation: 


  The Drupal 6 and 7 menu system stores menu item titles and descriptions in English. This allows the system to cache the data, but display to users using various languages on demand. For this to work, you should not use t() on the title or description of menu items in your hook_menu() implementation. Additionally, you should attempt to use a literal string (rather than a dynamic string) for these two keys, so the translation template extractor can find the string you used.


Emphasis mine.