Toot is usually accepted as a Saxon lookout hill. They had a knack of finding long barrows for these.
I suspect Yinys Cairn is the ruined corner of a hovel or bothy. I think there's traces of lime mortar between the lower courses ! I noticed that a collection of cairns, known in the North Pennines as curricks, have been listed on the Portal as a modern stone circle. They're not modern and they don't even slightly make a circle. (Tindale Fell).