Medium-sized hummingbird with a short straight bill. Overall drab grayish-green with a glittering green and yellow throat. Male has bright rusty cap. Occurs on the east slope of the Andes from southern Ecuador to Bolivia from around 2,100 to 2,700 m. Generally uncommon to rare. Forages in lower levels of forest edge, clearings, and shrubby roadsides. Rufous-capped Thornbill is longer-tailed than Tyrian Metaltail and is smaller and found at lower elevations than Rainbow-bearded Thornbill.