Their tail is dusky olive with thin white outer edges and tips on the feathers.

They have a dark brown iris, a needle-like black bill, and gray legs and feet.

It inhabits a variety of arid landscapes including thorn scrub, dry woodlands, cactus desert, and pastures with thorny shrubs; on the immediate coast it also occurs at the edges of mangroves.

It takes prey and fruits from foliage and twigs by gleaning while perched and by briefly hovering after a short flight.

The slender-billed inezia's song is "a flat, insipid trill, tleeeeeeee'e'e'e'e'e'e'e'e, thin and slightly descending or attenuated at end".

[7][8] "Although large expanses of suitable habitat remain within the species’ limited range, none is protected; moreover, substantial areas have been destroyed...as a result of overgrazing, firewood-gathering, tourist development and environmental pollution.