version 1 .
embeddedType EntityRef.Cap .

ActionDescription =
/ @spawnActor <spawn-actor @detail OptionalAny @initialAssertions #{protocol.Handle}>
/ @stopActor <stop-actor @error OptionalAny>
/ @inertCheck <inert-check>
/ <assert @target #:any @crossSpace bool @handle protocol.Handle @assertion any>
/ <retract @target #:any @crossSpace bool @handle protocol.Handle>
/ <message @target #:any @assertion any>
/ <sync @target #:any @callback #:any>
.

OptionalAny = <none> / <some @value any> .