The question above is a bit hard to answer. There are two ways we can think of the TOEFL, and depending on how you think, the answer might be “yes” or “no.”
If you compare the TOEFL to other English tests, you could definitely say that it is well made. That’s because it directly tests your actual English ability—how well you can understand and communicate.
In that, the TOEFL is different from many other English tests. There are no specific sections to test vocabulary or grammar, for example. Those skills are tested in the half of the test that is student-generated. That means the answers aren’t multiple choice, and there’s no “right” or “wrong.” Instead, actual English-speaking people listen to you and read what you’ve written and then judge how well they can understand you.
And that’s the real goal of studying English: to communicate. If you know thousands of phrasal verbs, have memorized all the words on your TOEFL flashcards and can answer every grammar question correctly, you still might have trouble communicating. The TOEFL avoids testing unnecessary information, and just goes straight to the usage of English—not knowledge of English.
If you forget about other English tests, though, and just consider the TOEFL compared to real-world English use, then you might decide the TOEFL isn’t so great.
For instance, unlike everyday, real-world English, the test focuses heavily on academic topics that you may never have seen before. Reading comprehension questions have trap answers that look good at first, if you’re not careful. TOEFL listening requires a lot of note-taking skill—something you might not do even if you speak English every day. And the speaking section gives you only a very short time to answer a question, sometimes as little as 45 seconds, which puts you under a lot of pressure.
All of that means that the test might surprise you (if you don’t prepare). In fact, the test can surprise native speakers, too.
So TOEFL scores don’t necessarily show your exact English ability. They’re not perfect, because they include many skills other than your English communication, including test-taking strategies, planning, pacing, and general familiarity with the test.
The good news, though, is that if your English is already very good, and you want your TOEFL score to show that fact, you can learn the test. After you’ve done that, it will be a much better representation of your English ability.