The offense may be overlooked to some degree for a new contributor but veteran contributors (including myself) know full well that all contributions should be one complete sentence.
This rule applies to the actual game-play contribution and not to the (usually italicized) dialogue. One sentence. Not two sentences. Not parts of sentences. One sentence containing subject and verb and whatever else is needed to complete the sentence just like you learned in first grade. Ellipses (...), while not officially banned, are very much discouraged because they make the Game Czar's head explode. Before hitting that submit button, re-read your contribution. Don't write the same way you talk. Think about what you've written. If it seems like 2 sentences, it if looks like two sentences, then it's probably two sentences. Rewrite it if you must to make it one clear well written sentence. PowerWorld LLC and TFWG (as I prefer) thank you for your attention to this matter.