Assuming this is the correct repo [1]. It has one dependency [2]. I would create a new package for ocitools. Although it has no exported symbols (no devel), they can be introduced later. And not everyone will want to install ocitools with runc at the same time. 

[1] https://github.com/opencontainers/ocitools
[2] https://github.com/opencontainers/runtime-spec

I don't see this as a big deal to install both at the same time.  ocitools is not a huge package (I don't think).  There is no library.  I have recently added man pages and bash completions to it.

Though extending the runc.spec with ocitools is fine, I would rather request for another package as both runc and ocitools can be maintained and updated separately. At least for consistency of packaged golang projects.

We will be shipping them together in RHEL at least for now. So I don't have a problem with setting up a different package, other then the pain of getting packages into Fedora.

Built as a separate package [1]

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1326277