Medium-sized, long-tailed, long-billed warbler. The back is olive-green and the underparts yellow. Found in montane habitats including bamboo, moist scrub, and forest edge. An active and energetic bird of the undergrowth. The distinctive song is an exuberant mix of downslurred and upslurred whistles and low rattles. Similar to African Yellow-Warbler, but in the areas where they overlap, mostly found at higher elevations, and distinguished by the olive-green, not black cap.