diff --git a/EvoScientist/model_registry/http_api.py b/EvoScientist/model_registry/http_api.py
index a8b3fef..cd54372 100644
--- a/EvoScientist/model_registry/http_api.py
+++ b/EvoScientist/model_registry/http_api.py
@@ -273,7 +273,20 @@ def _check_enabled_model(
         )
     auth_spec = spec.auth_specs[provider.auth.mode]
     credential_revision = 0
-    if auth_spec.credential_required and provider.auth.credential_id is not None:
+    if auth_spec.credential_required:
+        if provider.auth.credential_id is None:
+            # resolve_parameters already rejects this case; raise explicitly
+            # here so the five-tuple check never depends on call ordering.
+            raise ModelRegistryError(
+                CREDENTIAL_NOT_CONFIGURED,
+                f"Auth mode {provider.auth.mode!r} requires a credential reference.",
+                details=[
+                    {
+                        "path": "auth.credential_id",
+                        "code": CREDENTIAL_NOT_CONFIGURED,
+                    }
+                ],
+            )
         row = connection.execute(
             "SELECT current_revision FROM credential_pointers WHERE credential_id = ?",
             (provider.auth.credential_id,),
diff --git a/tests/test_model_registry_http.py b/tests/test_model_registry_http.py
index 46f1954..bedcdd9 100644
--- a/tests/test_model_registry_http.py
+++ b/tests/test_model_registry_http.py
@@ -443,6 +443,34 @@ def test_put_registry_rejects_unsupported_auth_mode(active_client):
     assert response.json()["code"] == "AUTH_MODE_UNSUPPORTED"
 
 
+def test_put_registry_rejects_capability_unsupported_by_adapter(active_client):
+    # Rule 8: declared capabilities must not exceed the adapter contract's
+    # protocol capabilities — the glm-5.2 contract declares vision=False.
+    registry = _current_registry(active_client)["registry"]
+    registry["providers"][0]["models"][0]["runtime"]["declared_capabilities"][
+        "vision"
+    ] = True
+
+    response = _put(active_client, registry)
+    assert response.status_code == 422
+    body = response.json()
+    assert body["code"] == "CAPABILITY_UNSUPPORTED_BY_ADAPTER"
+    assert "providers[0].models[0]" in body["details"][0]["path"]
+
+
+def test_put_registry_rejects_missing_credential_reference(active_client):
+    # The api_key AuthSpec requires a credential: credential_id=None must
+    # fail with CREDENTIAL_NOT_CONFIGURED, not a verification-tuple miss.
+    registry = _current_registry(active_client)["registry"]
+    registry["providers"][0]["auth"] = {"mode": "api_key", "credential_id": None}
+
+    response = _put(active_client, registry)
+    assert response.status_code == 422
+    body = response.json()
+    assert body["code"] == "CREDENTIAL_NOT_CONFIGURED"
+    assert "auth.credential_id" in body["details"][0]["path"]
+
+
 def test_put_registry_rejects_defaults_to_disabled_model(active_client):
     # With a bootstrap-state payload the schema-level check does not fire, so
     # the store's rule-7 guard (enforced on every save) is what rejects it.