Prophecies shouldn't be obvious. They should also make sense without giving away which cats it is about.

A bad prophecy would be the following if in the story, there were cats named Firetail, Stoneclaw, and Darktail:

"A fire will rise as it burns the stone from the dark."

For one, this prophecy doesn't work. It is also too obvious if the cat's prefixes were already mentioned. Don't give away the members of the prophecy in the prophecy. Or better yet, just don't make it obvious.

A good prophecy would be the following for those cats:

"A spark will strike a rock, and from it, a shadow will rise."

Or use numbers such as:

"Six will become two as midnight draws."

You may ask me in the comments if your prophecy is good. I can help you with that. :D