diff --git a/dokimi/changelog.d/20261113_120000_napetrov_ruf100-unused-noqa.md b/dokimi/changelog.d/20261113_120000_napetrov_ruf100-unused-noqa.md
new file mode 100644
index 000000000..b5142ccc2
--- /dev/null
+++ b/dokimi/changelog.d/20261113_120000_napetrov_ruf100-unused-noqa.md
@@ -0,0 +1,5 @@
+### Changed
+
+- **ruff now flags a stale `# noqa`** — RUF100 is selected, and the four `# noqa: F401` comments that silenced
+  nothing are removed. Codes of rules dokimi does not select (BLE001, E402, E731 and a few more) are listed in
+  `lint.external`, so their `noqa` comments stay. No runtime change.
diff --git a/dokimi/dokimi/eval/arm_runner.py b/dokimi/dokimi/eval/arm_runner.py
index 9440d3384..cf642893d 100644
--- a/dokimi/dokimi/eval/arm_runner.py
+++ b/dokimi/dokimi/eval/arm_runner.py
@@ -19,7 +19,7 @@
 from typing import Any, Dict, List, Optional, Sequence
 
 from dokimi.caching import is_empty_reply
-from dokimi.utils import question_id  # noqa: F401  (re-exported: callers import it from here)
+from dokimi.utils import question_id  # re-exported: callers import it from here
 from dokimi.artifacts import save_artifact
 from dokimi.llm import llm_call_with_usage
 from dokimi.defaults import DEFAULT_ANSWER_MODEL, DEFAULT_ANSWER_PROVIDER
diff --git a/dokimi/dokimi/harnesses/container_agent.py b/dokimi/dokimi/harnesses/container_agent.py
index 2cbcfb9bd..d047568f8 100644
--- a/dokimi/dokimi/harnesses/container_agent.py
+++ b/dokimi/dokimi/harnesses/container_agent.py
@@ -50,7 +50,7 @@
 
 from dokimi import docker_cmd, process
 from dokimi.docker_cmd import TASK_CONTAINER_HARDENING, Docker  # noqa: F401  (Docker is re-exported)
-from dokimi.docker_cmd import STEP_TIMEOUT_S as DOCKER_STEP_TIMEOUT  # noqa: F401
+from dokimi.docker_cmd import STEP_TIMEOUT_S as DOCKER_STEP_TIMEOUT
 
 from . import egress_proxy
 from .agent_sandbox import (
diff --git a/dokimi/dokimi/harnesses/docker_solver.py b/dokimi/dokimi/harnesses/docker_solver.py
index c91a3d571..e32d3992e 100644
--- a/dokimi/dokimi/harnesses/docker_solver.py
+++ b/dokimi/dokimi/harnesses/docker_solver.py
@@ -79,7 +79,7 @@
                              resolve_recorded, skill_needs, start_args, redact as _redact)
 from .skill_treatment import Treatment, build_plugin, check_skill, skill_listing, treatment_notice
 from .solver_stream import record_solver, run_solver
-from .task_env import _exec_env, unresolved_env  # noqa: F401  (re-exported)
+from .task_env import _exec_env, unresolved_env  # re-exported
 from .tbench_v1 import reward as _pytest_reward
 from .tasks import (  # noqa: F401  (timeouts re-exported)
     _DEFAULT_BUILD_TIMEOUT,
diff --git a/dokimi/dokimi/mcp/mcp_protocol.py b/dokimi/dokimi/mcp/mcp_protocol.py
index 0353a1aee..977fc62b7 100644
--- a/dokimi/dokimi/mcp/mcp_protocol.py
+++ b/dokimi/dokimi/mcp/mcp_protocol.py
@@ -33,7 +33,7 @@
 def _require_mcp():
     """Import the optional ``mcp`` SDK or raise a helpful error."""
     try:
-        import mcp  # noqa: F401
+        import mcp
         return mcp
     except ImportError as exc:  # pragma: no cover - exercised via tests with monkeypatch
         raise MCPConnectionError(
diff --git a/dokimi/pyproject.toml b/dokimi/pyproject.toml
index 64868be4e..1faec2c92 100644
--- a/dokimi/pyproject.toml
+++ b/dokimi/pyproject.toml
@@ -188,8 +188,6 @@ extend-exclude = ["benchmarks", "data", "tests/fixtures/task_formats"]
 # files above for 3.11:
 #   UP (pyupgrade) 1399, of which PEP 585/604 annotations 1185, imports 162
 #   I (isort) 156
-#   RUF100 (unused noqa) 22: most name rules not selected (BLE001, E402), so
-#   select those or list them in lint.external first
 # Hand fixes deferred because an open PR rewrites the same lines (#29, one
 # process runner for the spawn sites):
 #   PLW1509 (preexec_fn with threads) 1, PLW1510 (subprocess.run without
@@ -226,8 +224,10 @@ select = [
   "RUF006", "RUF008", "RUF009", "RUF013", "RUF016", "RUF017", "RUF018",
   "RUF020", "RUF024", "RUF026", "RUF028", "RUF030", "RUF032", "RUF033", "RUF034",
   "RUF040", "RUF048", "RUF049", "RUF053", "RUF060", "RUF061", "RUF063", "RUF064",
-  "RUF068", "RUF071", "RUF101", "RUF102", "RUF103", "RUF104", "RUF200",
+  "RUF068", "RUF071", "RUF100", "RUF101", "RUF102", "RUF103", "RUF104", "RUF200",
 ]
+# noqa codes of rules not selected here; RUF100 leaves them alone.
+external = ["ARG001", "BLE001", "E402", "E731", "N802", "N818", "S310"]
 ignore = [
   "A002",     # argument named like a builtin: keyword APIs mirror subprocess's input=
   "G004",     # f-string in a logging call: style, 108 sites