diff --git a/cli.py b/cli.py
index 04fb3890b1..b80ac20976 100644
--- a/cli.py
+++ b/cli.py
@@ -2999,8 +2999,10 @@ class HermesCLI:
                 )
 
         # Warn if the configured model is a Nous Hermes LLM (not agentic)
+        from hermes_cli.model_switch import is_nous_hermes_non_agentic
+
         model_name = getattr(self, "model", "") or ""
-        if "hermes" in model_name.lower():
+        if is_nous_hermes_non_agentic(model_name):
             self.console.print()
             self.console.print(
                 "[bold yellow]⚠  Nous Research Hermes 3 & 4 models are NOT agentic and are not "
diff --git a/hermes_cli/model_switch.py b/hermes_cli/model_switch.py
index 988983dbad..ace213add9 100644
--- a/hermes_cli/model_switch.py
+++ b/hermes_cli/model_switch.py
@@ -21,6 +21,7 @@ OpenRouter variant suffixes (``:free``, ``:extended``, ``:fast``).
 from __future__ import annotations
 
 import logging
+import re
 from dataclasses import dataclass
 from typing import List, NamedTuple, Optional
 
@@ -57,10 +58,36 @@ _HERMES_MODEL_WARNING = (
     "(Claude, GPT, Gemini, DeepSeek, etc.)."
 )
 
+# Match only the real Nous Research Hermes 3 / Hermes 4 chat families.
+# The previous substring check (`"hermes" in name.lower()`) false-positived on
+# unrelated local Modelfiles like ``hermes-brain:qwen3-14b-ctx16k`` that just
+# happen to carry "hermes" in their tag but are fully tool-capable.
+#
+# Positive examples the regex must match:
+#   NousResearch/Hermes-3-Llama-3.1-70B, hermes-4-405b, openrouter/hermes3:70b
+# Negative examples it must NOT match:
+#   hermes-brain:qwen3-14b-ctx16k, qwen3:14b, claude-opus-4-6
+_NOUS_HERMES_NON_AGENTIC_RE = re.compile(
+    r"(?:^|[/:])hermes[-_ ]?[34](?:[-_.:]|$)",
+    re.IGNORECASE,
+)
+
+
+def is_nous_hermes_non_agentic(model_name: str) -> bool:
+    """Return True if *model_name* is a real Nous Hermes 3/4 chat model.
+
+    Used to decide whether to surface the non-agentic warning at startup.
+    Callers in :mod:`cli.py` and here should go through this single helper
+    so the two sites don't drift.
+    """
+    if not model_name:
+        return False
+    return bool(_NOUS_HERMES_NON_AGENTIC_RE.search(model_name))
+
 
 def _check_hermes_model_warning(model_name: str) -> str:
-    """Return a warning string if *model_name* looks like a Hermes LLM model."""
-    if "hermes" in model_name.lower():
+    """Return a warning string if *model_name* is a Nous Hermes 3/4 chat model."""
+    if is_nous_hermes_non_agentic(model_name):
         return _HERMES_MODEL_WARNING
     return ""
 
diff --git a/tests/hermes_cli/test_nous_hermes_non_agentic.py b/tests/hermes_cli/test_nous_hermes_non_agentic.py
new file mode 100644
index 0000000000..179d26b7c9
--- /dev/null
+++ b/tests/hermes_cli/test_nous_hermes_non_agentic.py
@@ -0,0 +1,84 @@
+"""Tests for the Nous-Hermes-3/4 non-agentic warning detector.
+
+Prior to this check, the warning fired on any model whose name contained
+``"hermes"`` anywhere (case-insensitive). That false-positived on unrelated
+local Modelfiles such as ``hermes-brain:qwen3-14b-ctx16k`` — a tool-capable
+Qwen3 wrapper that happens to live under the "hermes" tag namespace.
+
+``is_nous_hermes_non_agentic`` should only match the actual Nous Research
+Hermes-3 / Hermes-4 chat family.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from hermes_cli.model_switch import (
+    _HERMES_MODEL_WARNING,
+    _check_hermes_model_warning,
+    is_nous_hermes_non_agentic,
+)
+
+
+@pytest.mark.parametrize(
+    "model_name",
+    [
+        "NousResearch/Hermes-3-Llama-3.1-70B",
+        "NousResearch/Hermes-3-Llama-3.1-405B",
+        "hermes-3",
+        "Hermes-3",
+        "hermes-4",
+        "hermes-4-405b",
+        "hermes_4_70b",
+        "openrouter/hermes3:70b",
+        "openrouter/nousresearch/hermes-4-405b",
+        "NousResearch/Hermes3",
+        "hermes-3.1",
+    ],
+)
+def test_matches_real_nous_hermes_chat_models(model_name: str) -> None:
+    assert is_nous_hermes_non_agentic(model_name), (
+        f"expected {model_name!r} to be flagged as Nous Hermes 3/4"
+    )
+    assert _check_hermes_model_warning(model_name) == _HERMES_MODEL_WARNING
+
+
+@pytest.mark.parametrize(
+    "model_name",
+    [
+        # Kyle's local Modelfile — qwen3:14b under a custom tag
+        "hermes-brain:qwen3-14b-ctx16k",
+        "hermes-brain:qwen3-14b-ctx32k",
+        "hermes-honcho:qwen3-8b-ctx8k",
+        # Plain unrelated models
+        "qwen3:14b",
+        "qwen3-coder:30b",
+        "qwen2.5:14b",
+        "claude-opus-4-6",
+        "anthropic/claude-sonnet-4.5",
+        "gpt-5",
+        "openai/gpt-4o",
+        "google/gemini-2.5-flash",
+        "deepseek-chat",
+        # Non-chat Hermes models we don't warn about
+        "hermes-llm-2",
+        "hermes2-pro",
+        "nous-hermes-2-mistral",
+        # Edge cases
+        "",
+        "hermes",  # bare "hermes" isn't the 3/4 family
+        "hermes-brain",
+        "brain-hermes-3-impostor",  # "3" not preceded by /: boundary
+    ],
+)
+def test_does_not_match_unrelated_models(model_name: str) -> None:
+    assert not is_nous_hermes_non_agentic(model_name), (
+        f"expected {model_name!r} NOT to be flagged as Nous Hermes 3/4"
+    )
+    assert _check_hermes_model_warning(model_name) == ""
+
+
+def test_none_like_inputs_are_safe() -> None:
+    assert is_nous_hermes_non_agentic("") is False
+    # Defensive: the helper shouldn't crash on None-ish falsy input either.
+    assert _check_hermes_model_warning("") == ""