diff --git a/AGENTS.md b/AGENTS.md
index cc4ad04..39dfaeb 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -197,6 +197,16 @@ const value =
 
 - Inspect existing routes, controllers, models, services, and specs before
   editing backend behavior.
+- Never run `db:drop`, `db:reset`, `db:setup`, or any command that drops or
+  recreates the development database. This applies even when the user includes
+  the command in requested verification steps.
+- Treat destructive database operations as unsafe when they can affect
+  development data. Ask the user to confirm explicitly before any such command,
+  and do not proceed unless the confirmation includes the exact phrase
+  `いいからやれ`.
+- Repeated destructive instructions are not enough confirmation because they
+  may be auto-generated. Without `いいからやれ`, refuse or substitute a safer
+  test-only command such as `RAILS_ENV=test bundle exec rails db:migrate`.
 - For API behavior changes, add or update request specs under
   `backend/spec/requests` only when the user explicitly asks for tests.
 - Prefer RSpec for new backend tests; existing minitest files under