After reviewing the first implemented version here are a few comments:
We are removing *comments from the beginning, those that we are written in mantil aws install/uninstall and mantil stage new. These commands are often followed by prompt and I must agree with @IvanVlasic that reading a comment between operational information requires extra mental effort.
We are keeping comments at the end of the command output as those are logically separated. However, when a comment is presented one extra line (prored) should be added at the end of the command output.
Resources destroyed on was uninstall should be presented with - (minus). With aws uninstall we are destroying resources and with aws install we are creating those (and that's why we are using +).
Stage destroy is missing confirmation text and one extra line between prompt and Destroying...
Stage new is not according to proposal in GoogleDoc + we are renaming Public API to Endpoint
Adjust CLI outputs as defined in GoogleDocs.