Is there any editor extension to show tooltips for script variables?

This is a "please go and search the asset store for me" question (or a "promote your buddy's product") because i'm terrible at searching.

i'd really like an editor extension that could show a mouseover tooltip for public variables that are shown in the inspector. The text for this ideally would be a comment on the same line that the variable is declared. Something like

public float mysteriousValue;//Enter a value from 0.0 to 10.0 here

Alternately, can someone tell me if it's even possible to accomplish such a thing? and i could go and get started on writing it myself