We received this question via Twitter this week from @AlexMorask: Would you happen to know [the] recommended length for [a] business description in Google Places and Google+?
And here's a reply that's a little longer than what Twitter allows per tweet:
In the old Google Places dashboard the limit was a measly 200 characters. Hardly enough to say anything.
In the new Google Places for Business dashboard & on G+ Pages for local management interface, the limit is not nearly so Scrooge-like. Still, the description should be short and sweet. It should be an elevator pitch that convinces a reader and potential customer with brevity. If it is too long, it pushes your (hopefully) good reviews down the page making them less visible to a reader and requiring them to scroll to see them.
So the recommended length? You should use just enough words needed to describe what you do in a compelling way.
Interesting Factoid: The maximum number of characters in the description field of the new Places dashboard: 4491 including spaces. I do not recommend that you use them all.
Second Factoid: The description field theoretically supports rich text and links but that feature does not yet work.
As a side note, according to Google the content of the description is no longer used in ranking. I haven't tested that but it makes sense as that field was so widely abused with useless spammy content. That is likely also the reason that Google stopped showing it on their front page and replaced it with a few sentiment snippets. They obviously assume that they can calculate a few words about your business better than you can describe it briefly. Whether that is true or not, I am not sure.
The other reality is that very, very few people make it to that page. Google thinks about your G+ Page as one syndicated result amongst many for the trusted data about your business that comes from the dashboard and other sources. In fact with the recent changes to the way results are displayed on the home page, it now takes from 2 to 4 clicks to get from a search result to your G+ Page that includes your description.
Most SMBs think of the G+ Page for local as their page and the repository of their information. Google doesn't view it that way. They store the local data that they get from you and from around the web in a canonical record in their knowledge graph and then "syndicate" that content to the various software and hardware platforms where it will be useful. That could include Google Maps, the G+ Page for Local, Google Glass or most importantly, the front page of Google where it is seen by far and away the most. As such, I wouldn't worry too much about the description field as it is one piece of data that is only syndicated to + Page and rarely seen elsewhere.
(Photo by Scott Akerman and used via Creative Commons licensing.)