What changed
Google analyzed more than 913,000 coding-agent sessions and reports that 13% encountered inline TODO or FIXME bug references. In 6% of encounters the agent acted on the reference, 83% without a user request, adding 70% more steps, 77% more tokens and 105% more wait time after controls.
Why it matters
Repository debris is now executable context for agents. Stale tickets and comments can cause unrequested investigation or edits, so code hygiene becomes a reliability and cost control rather than only a maintenance preference.
What to do
Scan agent-visible repositories for stale bug references, resolve each against the tracker, delete only references shown to be obsolete, and add a presubmit rule that flags new issue references without a live status check or explicit scope instruction.
Caveat
The data comes from Google's internal sessions and TODO conventions, not an independent cross-vendor sample. Bug references are a proxy for distraction, and the reported regressions do not prove that every extra step was harmful in another codebase or harness.