Build the tool only when the query has genuine action intent that text cannot satisfy, the search demand justifies the development cost, and the result gives you a defensible, linkable asset that is hard to copy. The decision is not “tools are good for SEO” or “tools are a distraction,” it is a test the specific query has to pass on all three points. When a query’s intent is to do something rather than read, when enough people search it to repay the build, and when a working tool becomes an asset others link to and struggle to replicate, the build is justified. When any of those fails, an article is the better use of effort.
Start with intent, because it is the gate. If the searcher wants to read and understand, a strong page already satisfies them and a tool adds nothing, so the build is wasted. Only when text leaves the user with work still to do, a calculation to run, a value to generate, a file to convert, does the tool earn its place. That is the action intent text cannot close, and it is the first condition. Without it, skip the build no matter how appealing the project sounds.
The second and third conditions are about return. Building and maintaining a tool costs real development time, so the demand has to be large or valuable enough to repay it, and the tool has to be something competitors cannot trivially clone. A good tool tends to attract links and references on its own, which is part of why it ranks, and that defensibility is what turns a one-time build into a lasting asset. A tool nobody searches for, or one a rival rebuilds in an afternoon, fails this half of the test even when the intent is right.
To decide, take the query and run all three checks in order. Is the intent to do, not read? Is the demand large enough to repay the build? Will the tool be defensible and linkable once it exists? Build only when all three hold, and write a page instead whenever one of them does not. Reserve tool development for real action intent that justifies its cost, and let content carry everything else.