So, in YaRDoc format, I believe this would be [return](http://rubydoc.info/docs/yard/file/docs/Tags.md#return), [see](http://rubydoc.info/docs/yard/file/docs/Tags.md#see)

    # Build a nicely formatted list of built-in
    # formatter keys and their descriptions
    # @see MetricFu::Formatter::BUILTIN_FORMATS
    # @return [Array<String>] in the form of 
    #    "   <key>  : <description>."
    def format_descriptions