the one that oldgoaly is showing looks like one for the old automobile split rings, used to remove and reinstall.
the one that Jimwrench shows, looks like a tool to install the wooden spokes.
looking at the picture, possibly the round opening would go over the spoke and the ? left side flat end with the lip
would rest against the inside of the rim. ( just a guess)
I think the old wood ones were called spoke dogs ???