diff --git a/cli.py b/cli.py
index 1ba5071ed..05015752a 100644
--- a/cli.py
+++ b/cli.py
@@ -371,7 +371,6 @@ def load_cli_config() -> Dict[str, Any]:
         },
         "delegation": {
             "max_iterations": 45,  # Max tool-calling turns per child agent
-            "default_toolsets": ["terminal", "file", "web"],  # Default toolsets for subagents
             "model": "",       # Subagent model override (empty = inherit parent model)
             "provider": "",    # Subagent provider override (empty = inherit parent provider)
             "base_url": "",    # Direct OpenAI-compatible endpoint for subagents
diff --git a/tests/hermes_cli/test_config_drift.py b/tests/hermes_cli/test_config_drift.py
new file mode 100644
index 000000000..4b49c58b1
--- /dev/null
+++ b/tests/hermes_cli/test_config_drift.py
@@ -0,0 +1,25 @@
+"""Regression tests for removed dead config keys.
+
+This file guards against accidental re-introduction of config keys that were
+documented or declared at some point but never actually wired up to read code.
+Future dead-config regressions can accumulate here.
+"""
+
+
+def test_delegation_default_toolsets_removed_from_cli_config():
+    """delegation.default_toolsets was dead config — never read by
+    _load_config() or anywhere else. Removed in M0.5.
+
+    Guards against accidental re-introduction in cli.py's CLI_CONFIG default
+    dict. If this test fails, someone re-added the key without wiring it up
+    to _load_config() in tools/delegate_tool.py.
+    """
+    from cli import CLI_CONFIG
+
+    delegation_cfg = CLI_CONFIG.get("delegation", {})
+    assert "default_toolsets" not in delegation_cfg, (
+        "delegation.default_toolsets was removed in M0.5 because it was "
+        "never read. Do not re-add it; use tools/delegate_tool.py's "
+        "DEFAULT_TOOLSETS module constant or wire a new config key through "
+        "_load_config()."
+    )