I like it - I've also had your experience with the other Ruby documentation formats (RDoc can become too messy, YARD too many @tags). One potential suggestion:

I like it - I've also had your experience with the other Ruby documentation formats (RDoc can become too messy, YARD too many @tags). One potential suggestion: It might be worth adding some indication of how to specify a duck-type (rather than a Class) in the arguments section. (i.e. "name - The name of the object; should respond to to_s", or hopefully something less clunky than that)