Firstly, no marks are deducted for exceeding the word limit as long as you keep the answer to the point.
Though you can write your answer in your own way, it should contain the answer for what exactly has been asked for.
For example, you cannot write a lengthy sentence to ‘Fill in the missing blanks.’
Make a note of the word limit depending on the marks allotted for that question. You cannot write 6-10 lines of an answer when the marks allotted are for 1 or 2.
Another reason to watch your word limit is the duration of the exam. Write the important points in a lengthy answer & highlight them. This way, you can limit your writing and save time.
If a question carries 10-15 marks, write at least 15 points to score 1 mark for each point and you can add more information if you have further to write.
Another reason to limit your wording is to avoid spelling errors. Unless, the question demands a lengthy answer, never exaggerate it to avoid unnecessary spelling mistakes.
Though there is no direct prescription for word limit, the marks allotted for questions and the type of questions describe the word limit for answers in CBSE Board Exam 2023.