This is a plugin that adds support for the two HTML metas â€˜keywordsâ€™ and â€˜descriptionâ€™. Copy and paste the following code to a file called xfish_meta.php and put it in your wp-content/plugins directory, then enable it in the plugins section.
You can give each post custom fields named â€˜keywordsâ€™ and â€˜descriptionâ€™. The keywords one is a list of keywords for that post separated by commas without any trailing or leading ones, description consists of a few sentences (finish the description with some punctuation mark, like a full stop).
If the requested page consists of several posts (like the main index of your blog), all the available keywords and descriptions get pasted together into the respective meta directive.