I wrote סוס יפה, but it was not accepted. Isn't it correct? Android keyboard has no niqqud...
It seems to accept it now, although it still warns of a typo.
This is a sentence fragment and should not have a period.
Sentence fragments go against commonly accepted style, but are still grammatical. Most people wouldn't have any problem writing "Nice job." Or "Poor form."
How would you say "that's a pretty horse."