Writing level relies on your vocabulary skill, especially in the academic writing test. Studies show that your vocabulary range and accuracy impact at least 25% of your writing band. So, writing vocabulary is very important to improve writing skills.
In general, students' writings are around hundreds of words. If you want to have a good score, you cannot use generic or basic words thoroughly. Try to highlight your idea with 5-7 hard or low-frequency words that are similar to the following 100 words. It will impress the examiners or readers that you have strong vocabulary skills.
You may think the list is too short. However, writing isn't like reading; in reading, you cannot choose words, but in writing, you can select words by yourself. So, these 100 words can play a significant role in your writing. Of course, you can extend your writing vocabulary if you want to get a higher level.
Word List
Spelling Exercise