IMO, as long as you don't actually link to it, it's acceptable.
The thing is that you're describing how you found something. You're not praising it, you're not directly leading traffic to it, you're stating a fact: you found an answer by searching those terms. From a story-ID searching point of view, I think this is great!1 After that, it will be up to the querent and future readers to decide whether they want to read it online, buy it, borrow it from the library, etc. This is not the site's responsibility.
However, some users seem to think it is the site's responsibility to not even mention such copyright-infringing sites. At the same time, Stack Exchange sites are not only about getting your questions answered, they're also about learning how to get better at researching and answering your own questions. Part of the site's responsibility is also to provide you with guidance, the thought process to adopt, and including search results does that.
The dilemma would be that:
- you taught somebody how to search
- but you admitted that the way you did it infringed on some laws.
Personally, I think the benefits of teaching a man to fish outweigh the cons of having to break a public tree's branch to get the fishing stick. It's not overly unreasonable to tell someone you used what is, in story-ID searching, a pretty well-documented database. Mentioning the practice isn't praising it, and I'm of the opinion that we should assume people aren't stupid enough to think it's the only way. Folks (be it querents or other people trying to Google story-ID answers) can think for themselves and adapt their ways of searching to legal-friendly stuff.
I don't want to downplay copyright infringement matters, I know it cuts off authors and publishers from loads of money, but fig-leafing their existence to the detriment of useful information is, IMO, contrary to the mission of Stack Exchange sites.
This edit in particular is, quite frankly, destructive. At the very least, the keywords bit of your search query are info to be kept in the answer, and had I seen this in the Suggested Edits queue, I'd have rejected it, with a custom reason along the lines of my explanation above. I may have rejected and edited it into something along the lines of:2
Found with a search for site:mangakakalot.com magic phone app
Found with a search for magic phone app
, and filtering results by a particular manga-reading site.
1 I've told you this already, and will continue to do so: you including your successful queries greatly helped me improve my Google-fu skills, and I'm really grateful for it.
2 I won't do it straight away, as we're currently discussing this answer on Meta, but the rollback/edit button is itching me.