Sometimes cookbooks have a mode (enabled by CLI flags) that makes them print/list some information without performing any RW action.
In those cases is most often unnecessary to log to IRC/SAL and running the cookbook with the debug mode could trigger very noisy loggers and make the output less readable.
One way to solve this could be to offer a dedicated exception that the cookbooks could raise from their __init__ and that Spicerack could catch. In that case the cookbook will be considered "successful" and spicerack will make it exit cleanly without ever executing run() and hence without any start/end logging.
This will also cover and solve some of the use cases of T324655.