Marker attribute for the rpc method handler. It is mostly the same with StreamJsonRpc.JsonRpcMethodAttribute Using this instead of StreamJsonRpc.JsonRpcMethodAttribute will affect the startup behavior of the plugin, so that c-lightning will expose the rpc endpoint to users and the call to c-lightning will be bypassed to the plugin. An argument description and longDescription is a message that users will see in a help call to c-lightning.