To get the next n entries, one can create a URL where the argument last has the value from tags[len(tags)-1]. If there are indeed more results, the URL for the next block is encoded in an RFC5988 Link header, as a "next" relation.

However, conformance tests are testing for n=0 case.

So, for tags list with n=0, what is the expected response? we return nothing because n=0, but "last" needs to be set because there are indeed more, but since nothing was returned, how does one set "last"?

With n=0, this requirement cannot be met as it is stated