Generating HTML meta description tags

I'd like my HTML output to include a meta tag that describes the book to aid in SEO. Something like this:

<meta name="description" content="Describes the tasks required to set up and maintain a store built with XYZ Commerce Cloud, for example creating the product catalog, editing page layouts, configuring payment methods, and managing shopper communications. Intended for all audiences."/>

Where in the transform is this pulled? Could I put this in a property file instead of the source file? I can't quite see where you turn on generate.meta.abstract, and where it gets the content.

I'm using docbook-xsl-ns-1.76.1, docbook-5, fop-1.1, apache-ant-1.8.1, and saxon-9-2-1-1.

Rob Flynn
Principal Technical Writer