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 @crossSpacePins CrossSpacePins @handle protocol.Handle @assertion any>
/ <retract @target #!any @crossSpace bool @handle protocol.Handle>
/ <message @target #!any @assertion any>
/ <sync @target #!any @callback #!any>
.

CrossSpacePins = @none #f / @some [#!any ...] .

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