[1][3] The specific name kopsteini honours Felix Kopstein, Austrian physician and naturalist who collected the type series in 1924.

[3][4] The type series of C. kopsteini consists of two adult males measuring in snout-to-vent length (SVL) 41–42 mm (1.6–1.7 in) and an adult female measuring 45 mm (1.8 in) SVL.

The finger and toe tips bear small discs; webbing is absent.

The underside is dirty gray-brown, with diffuse, light gray spots.

This species is likely to be threatened by extensive logging taking place on Sanana Island.