Find Untested Sources Purpose Coverage tools answer "which lines were executed?" — they require a green build and a passing test run, which is minutes-to-tens-of-minutes on a real repo. The question this skill answers is different and much cheaper: Which source files have no test file referencing any of their declared types/symbols? That's the question an agent asks before writing a new test — and it can be answered statically in a few seconds by parsing source files, with no build, no dependency resolution, and no compilation . The output is a deterministic test-pairing map that lets the age…