diff --git a/.codex/skills/agentopt/SKILL.md b/.codex/skills/agentopt/SKILL.md
index cf99bfc..8f792f4 100644
--- a/.codex/skills/agentopt/SKILL.md
+++ b/.codex/skills/agentopt/SKILL.md
@@ -69,7 +69,7 @@ results.export_config("artifacts/best_config.yaml")
 print("best:", results.get_best_combo(), "cost:", results.selection_cost)
 ```
 
-A working fuller version lives at `examples/custom_agent_example.py`.
+A working fuller version lives at `examples/selection/local/custom_agent.py`.
 
 ---
 
diff --git a/src/agentopt/routing/config.py b/src/agentopt/routing/config.py
index b7f199c..fd1bda8 100644
--- a/src/agentopt/routing/config.py
+++ b/src/agentopt/routing/config.py
@@ -66,7 +66,9 @@ def _resolve_class(policy: str) -> Type[Router]:
     except ImportError as exc:
         raise ValueError(
             f"Could not import routing policy module {module_name!r}: {exc}. "
-            "Custom routers must be importable on the daemon's PYTHONPATH."
+            f"Restart the daemon with `agentopt serve --policy-module "
+            f"path/to/{module_name}.py` so the file is pre-imported, or put "
+            "its parent directory on the daemon's PYTHONPATH before starting."
         ) from exc
     try:
         cls = getattr(module, class_name)