You can’t score a daily horoscope the way you score a weather forecast, as a percentage of hits. Astrology is a tradition of reading the sky, and nobody has shown it predicts events. What you can judge is whether a horoscope actually comes from the current sky or is a general text with no link to where the planets are. A well-made horoscope responds to where the Moon is right now, what phase it’s in, and what aspects it’s making to the other planets. A text that would work unchanged on any other day of the year didn’t come from the sky, however nicely it’s written.
The second measure is specificity. A horoscope that repeats lines like “today holds something interesting” or “stay open to new opportunities” has little value, because it fits everyone and no one. A useful daily horoscope ties itself to concrete areas of life (love, career, health, money) and gives you something to work with: where to push today, where to wait, what deserves your attention.
The third measure, the one people forget, is honesty. A horoscope for a sign works only with the Sun, meaning your birth date, and describes the shared tone of the day for everyone born under that sign. It can say that a Scorpio Moon tends to make Taurus touchier about what’s said, and that a money talk can wait a day. It can’t say that a specific person will call you this afternoon. A horoscope that claims the second isn’t more accurate. It’s just bolder, and time usually settles the matter.