Yes, that's fine.
The 25-word limit uses 6 characters as the average length of a word, with each space between a word also counting as an additional character. (Punctuation counts as a character too.) If your sentence(s) contain words of shorter length, you might be able to squeeze 29 to 30 words in the space -- and that's okay. However, the program will not allow you to enter more than 175 characters.