Sure. But that still doesn't tell me exactly which arguments they take. Or give me an opportunity to debug the code when it doesn't do as I expect. I realise that it just-works (tm). It's when it doesn't, it gets problematic.
For:
story GET /story/:id(.:format) story#show
story_path(id)
story_path(id, format)
story_url(id)
story_url(id, format)