Awesome, this is the final confirmation. Skills are being discovered correctly (they show up in Settings and in the slash menu), but they’re not getting injected into the <available_skills> section of the system prompt. So this is a bug in the injection stage, not discovery.
I filed an internal report with a link to this thread and your SKILL.md example. I can’t share an ETA for a fix yet, but we’ll post an update here once we have one.
For now, your workaround with a rule that lists the skills is totally fine if you don’t want to wait.