I have done exactly this as recently as yesterday, so I’m not sure why it doesn’t work for you.
https://github.com/anthropics/claude-code/issues/92769
The <command-args> I know because I just audited my raw Claude transcripts via ccglass. You can verify by just asking Haiku "hey, /grill-me does this skill autoload for you?" and then "/grill-me hey, how many times does this text appear in your context?"
You can trivially doublecheck me. The above prompts won't even eat 1% of a 5 hr on 20$ plan.
(And I didn’t know the double args thing, that’s very interesting! I should have said I only meant the first bit.)