Disavow

The disavow tool lets you upload a list of links or domains you'd like Google to ignore when assessing your site. It lives in Google Search Console. It was created after link spam became a widespread problem.

Google says most sites don't need it. Its systems already ignore many bad links. It makes sense if you have a manual action for unnatural links, or if you know you've got a pattern of paid or spammy links that you can't get removed. A mistaken disavow file can also remove helpful links, so use it carefully.

Practical point: try removal first. Contact the site owner and keep a record. If that fails and the problem is serious, build a file with specific domains, upload it, and note the date. Don't disavow links just because a tool shows a high toxicity score. Review them manually and keep the file small and justified.