As a longtime auction rat and volunteer I can definitely say:
Don't worry too much about the description. Unless their is something special or unique about the game, the box will do most of the talking for you. There simply isn't time to read a wall of text when we have push an item across the stage every 30 seconds.
If you say it's complete or near mint, it needs to be or you run the risk of your buyer inspecting it and having it returned.
Use painters tape, the blue or green masking kind. This is what we use to attach tags and seal boxes that come loose on everything but the most collectible of items. Don't use scotch/packing tape unless it is going on plastic/shrink.
Echoing what Hahnarama said: PRICE TO SELL, if you don't want to bring it home, then make your consignment store price for Saturday whatever you would be willing to get to not have to schlep it back across the country. Be reasonable with your reserves, a higher reserve may scare away bidders who could get "roped in" with a smaller starting bid.
Do NOT expect to get retail pricing unless your game is rare/oop/extremely desirable.
You can get a good idea of what to expect for pricing by checking last years data, but don't take it as gospel. I've had items I paid $20 for in previous years go for $5 and others that I paid $10 for sell for $50 the following year.
Make sure you attend the TOVA section of the auction. Saturday afternoon prior to the charity auction. Best 3-5 hours of the entire con!
Do not waste your time with mass produced family games: there are mountains of Scene It, apples to apples, trivia and word games that don't sell for anything every year.