A spanner? Nah...Actually, the script already outputs a description for:
- posts and Pages => abbreviation of excerpt or content
- category queries => category description
- everything else => blog "tagline"
Possibly the only things missing are the ability to override single posts/Pages with a custom field, and a different default description than the blog's tagline. Easy peasy:
Version 0.4 now has 4 user-configurable variables:
Default description (if set, will override use of blog tagline).
Length in # of words for a post/Page description.
1 (default) = use excerpt (if exists) for description.
0 = force use of content at all times.
Custom field key; if exists, overrides use of excerpt/content for post/Page description.