Current text-pretty description says,

Use the text-pretty utility to prevent orphans (a single word on its own line) at the end of a text block:

See this recent blog post from Webkit about text-wrap: pretty; and in particular,

Because of the way Chrome’s implementation of pretty has been taught, a lot of web developers expect this value is only supposed to prevent short last lines. But that was never the intention. In fact, the CSS Working Group defined a different value for such a purpose. It was just renamed last week to text-wrap: avoid-short-last-lines.

So it seems an updated description is needed and this PR has a first attempt.