Homer often said that Odyssey short of content about ring (5)

'homer often said that odyssey short' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'content about ring' is the wordplay.
I cannot really see how this works, but
'content' could be 'do' (DO is an example) and 'do' is located in the answer.
'ring' could be 'o' (letter resembling a ring) and 'o' is found in the answer.
This explanation may well be incorrect...

'of' acts as a link.

Can you help me to learn more?