Once upon a time

Cameron Boyce, who died this summer, doesn't get much of the spotlight in "Descendants 3," but the fairy-tale franchise has always been more about girl power. In what's billed as the last chapter, Dove Cameron and her female co-stars get the best songs and dance moves, with director/choreographer Kenny Ortega bringing his magical touch. You may not think the movie dazzles as much as the MGM musicals; your kids will beg to differ.

7 p.m. Friday, Disney Channel

More than a fantasy

"Worlds of Ursula K. Le Guin" gives fellow sci-fi writers a chance to sing the icon's praises, including Neil Gaiman and Michael Chabon. But this "American Masters" documentary is most powerful when we hear from teenagers just now being wowed by works like "The Left Hand of Darkness," a reminder that great novels are timeless.

9:30 p.m. Friday, TPT, Ch. 2

A sketchy start

Comedian Robin Thede has assembled a strong cast for "A Black Lady Sketch Show" and even recruited big names like Angela Bassett and Kelly Rowland to make cameos. But too many of the early bits feel like outtakes from an improv class.

10 p.m. Friday, HBO

Le Guin

The real jungle book

Oscar winner Lupita Nyong'o narrates "Serengeti," a six-part series about the daily triumphs and struggles of animals in northern Tanzania. The stars include Tempo, an elephant wobbling into adulthood, and Bakari, a baboon committed to raising an orphaned child.

7 p.m. Sunday, Discovery Channel

Neal Justin