Just the strikes, quotes, buy/sell and a short commentary is all that's needed. Then everyone is on the same page. Yes ..... Stated on Saturday when the final quotes were in for the Jan18 options.
Lots of people would go short that straddle. Lots of people would go long it. For you to have gone long it, someone else would have gone short it. So it is an unreasonable assumption to assume the direction when trading volatility. Do you call your broker and say "I want to trade 20 straddles" and they automatically assume you will be a buyer?