Cactus-Like Plant with White Dots Declining: Likely an Agave

A Walmart purchase years ago: a spineless, starburst-shaped plant with pointy leaves and white dots, now tea-saucer sized, producing offsets but turning brownish-red and dying. The expert suspects an Agave relative. Without a photo, exact ID is uncertain, but care advice for tropical/succulent plants applies: protect from temps below 45°F, avoid harsh direct sun (causes reddening), water by weight (soak, drain, wait until pot feels light). Cacti tolerate more drying than leafy plants.