This is a cist, a box-like grave constructed from flat stone slabs set on edge, typically used during the Bronze Age to contain a single crouched burial or cremated remains. The Teeskagh example is classified as a long cist, meaning its internal dimensions are notably elongated rather than roughly square. What remains today is a single long southern slab running about two metres east to west, and a fragment of a smaller slab at the eastern end of the northern side, giving a sense of an internal width of around 0.6 metres. A scatter of loose flagstones just outside the north-eastern corner may once have formed part of the same structure.

When the antiquary Thomas Johnson Westropp visited and recorded the site in 1905, the cist was in considerably better condition. His sketch plan showed a complete northern slab measuring 1.57 metres in length, with smaller slabs still in place at the eastern and western ends, forming a more legible chamber. In the decades since, stone has shifted or been removed, and the structure has deteriorated to its current fragmentary state. Ruairí de Valera and Seán Ó Nualláin later examined the site as part of their systematic survey of megalithic tombs across County Clare, published in 1961, and formally identified it as a long cist. The cairn within which the cist sits, a mound of loose stones heaped over or around a burial feature, would originally have marked the spot as a place of significance in the landscape, though much of that cairn material has itself dispersed over time.