Like Greywether I thought the Canmore fieldnotes a tad harsh as it looks like, to me, that someone (must have been a giant) has roughly pushed the whole thing side ways. Capstones have been scattered but the chamber appears 'reasonably' all there but fallen in. Side stones, as described by Greywether, remain in place.
Both of us seem to agree more with Henshall's description :
Tigh Chloiche, South Clettraval, a chambered cairn, has been much disturbed by secondary buildings and its present form bears little relationship to its original plan.
The narrow and almost parallel-sided chamber is surrounded on the N, E and S by traces of what appear to be circular buildings. Four orthostats of the chamber remain on the SW but the northern part cannot be traced. The entrance was from the E but nothing can be seen of the passage walls. Large flat stone slabs lie displaced outside the chamber and, whereas the extent of the cairn is fairly well marked to the N. and E., it drops to an extensive low spread to the S and SE.
Finds of potsherds are in the National Museum of Antiquities of Scotland (NMAS).
A S Henshall 1972, visited 2 May 1962.
The size of the site, almost 19m wide and 1.5m tall, suggest cairn. Nobody can dispute the views!
Having read Canmore and other reports before the visit, I had expected to be underwhelmed by this site.
Comments like "has been much disturbed by secondary buildings and its present form bears little relationship to its original plan" do not raise expectations.
To my eyes, what you actually get is a well fairly well preserved Hebridean Passage Grave with a lintelled passage plus chamber with a few side stones still standing a most of the rest fallen into the chamber.
Any secondary building was limited to the outside cairn material and, reading the reports again after the visit, maybe that's what they meant.
But don't be put off. This is a site worth visiting especially if you've come to see Clettraval anyway.