In principle, the description can be modified, but the prerequisite is that it cannot go beyond the scope of the original description and claims. If you think that the modification of the claims requires explanation, you should make it in the statement of opinion, and It’s not about introducing new content into the manual. If you don’t introduce new content, your modifications to the manual won’t be necessary. Generally, the modifications made when replying to the opinion notice are consistent modifications in response to the changes in the claims, that is, the content of the invention is modified into a consistent form after the modification of the claims.