well in a loose coupled environment things might go downhill, the non configured neighbor was just one example.... I would probably want some feedback if the command was well formed and makes sense... wouldn't I? Also since I feel like the API changes over time even if it is just additions. Some form of feedback seams handy to me!?!?
maybe an api stanzer to "subscribe" to it and then you get some json reflectiong the command, the "exit status" like $? and the reactor string as detailed (human readable) failure description. Something like that?