The Dead Tool Nobody Can Remove From the Registry
A tool has been sitting in your shared agent catalog for fourteen months. It was wired up by an engineer who has since left, for a workflow that was sunset two reorgs ago, against a backend service whose owners are no longer sure who they are. The tool definition is 380 tokens. It ships in every system prompt for every agent in the org, on every turn, because nobody can prove it is unused, and the cost of being wrong about that proof is higher than the cost of carrying it forever.
That tool is the database column nobody dares drop. It is the cron job whose log file rotated out years ago. It is the dead code path you can grep for and find zero references to, except eval() exists and you cannot be sure. The agentic version of this problem is worse, because the carrying cost is not merely some bytes on disk — it is paid in tokens, in selection accuracy, and in security surface, on every single inference your platform runs.
