IMHO, since TDD focuses too much on code implementation and is tightly coupled with the code (simply, method names and parameters must match), this metric still does not mean you're safe. If your tool allows you to see the lines of code covered by tests, you can use it to see the parts of the code that are NOT covered by any test - then you can write, if necessary, some more tests. However, in general I think that following the Test Diamond strategy is more beneficial (if you don't know what it is, here's a short introduction: https://www.code4it.dev/architecture-notes/testing-pyramid-vs-testing-diamond/ )
