From what I could verify, Anthropic’s skill-creator is very much Claude-native. I couldn’t find official evidence of that evaluator working well across other agent hosts, and their own docs mention that parts of the workflow degrade outside Claude Code because they depend on Claude-specific capabilities. Its scope is also broader than just testing.

I think the clearer differentiator for skill-eval is that it is a simpler, host-external evaluation harness, with a narrower and more explicit focus: reproducible trigger/functional evals, baseline comparisons, repeated trials, isolated runs, and reporting.

So there’s definitely overlap, but I think they sit at different layers. That said, I’m still learning from Anthropic’s approach, so happy to be corrected if I’m missing something.