diff --git a/litellm/proxy/_experimental/mcp_server/toolset_db.py b/litellm/proxy/_experimental/mcp_server/toolset_db.py
index f13b1c72558..750ff2428a4 100644
--- a/litellm/proxy/_experimental/mcp_server/toolset_db.py
+++ b/litellm/proxy/_experimental/mcp_server/toolset_db.py
@@ -132,9 +132,8 @@ async def update_mcp_toolset(
     data: UpdateMCPToolsetRequest,
     touched_by: str,
 ) -> MCPToolset | None:
-    """A partial update: a field the caller left out keeps its stored value and a
-    field sent as null is cleared, where a null ``tools`` is an empty list and a null
-    ``toolset_name`` is ignored because a toolset always has a name."""
+    """A partial update: absent keeps, null clears, except that a toolset always has a
+    name, so a null ``toolset_name`` is ignored."""
     data_dict: Final = data.model_dump(exclude_unset=True, exclude={"toolset_id"})
     if "tools" in data_dict:
         data_dict["tools"] = json.dumps(data_dict["tools"] or ())
diff --git a/tests/e2e/proxy_client.py b/tests/e2e/proxy_client.py
index 47c5d0abaff..ea6cc191e63 100644
--- a/tests/e2e/proxy_client.py
+++ b/tests/e2e/proxy_client.py
@@ -542,8 +542,11 @@ class ProxyClient:
         """The replicas that serve `path`: every data-plane replica for an LLM route,
         and for a management route the control-plane replicas, which in a split
         deployment is the one service that serves it (the data-plane replicas trim
-        management routes) and in a monolith is every replica."""
-        return self.control_replicas if is_control_plane_path(path) else self.replicas
+        management routes) and in a monolith is every replica. Never empty: a
+        read-back against no replica would assert nothing and pass."""
+        replicas: Final = self.control_replicas if is_control_plane_path(path) else self.replicas
+        assert replicas, f"no replica is configured to serve {path}, so a read-back there would prove nothing"
+        return replicas
 
     def read_back_everywhere[R: BaseModel](
         self, path: str, response_type: type[R], *, settled: Callable[[R], bool]
diff --git a/tests/e2e/test_e2e_http.py b/tests/e2e/test_e2e_http.py
index 6ab35dd6cd5..d0807226627 100644
--- a/tests/e2e/test_e2e_http.py
+++ b/tests/e2e/test_e2e_http.py
@@ -177,7 +177,7 @@ _JSON: Final[TypeAdapter[object]] = TypeAdapter(object)
 
 @dataclass
 class FakeJsonResponse:
-    """The `_classify` view of a response: a status, the raw body bytes, and the
+    """The `classify` view of a response: a status, the raw body bytes, and the
     parse that would raise on an empty one."""
 
     status_code: int
diff --git a/tests/e2e/test_proxy_client.py b/tests/e2e/test_proxy_client.py
index 88931525c12..474aaf210c2 100644
--- a/tests/e2e/test_proxy_client.py
+++ b/tests/e2e/test_proxy_client.py
@@ -13,10 +13,9 @@ from __future__ import annotations
 from collections.abc import Iterable, Mapping
 from dataclasses import dataclass
 from itertools import chain, repeat
-from typing import Final
+from typing import Final, cast
 
 import pytest
-
 from e2e_config import parse_replica_urls
 from e2e_http import Success
 from models import ModelListEntry, ModelsListResponse
@@ -25,14 +24,17 @@ from proxy_client import (
     ModelsPoller,
     NeverConvergedOn,
     NotServableOn,
+    ProxyClient,
     ReplicaRead,
     Servable,
     await_everywhere,
     await_servable_everywhere,
     build_proxy_client,
 )
+from transport import Transport
 
 MODEL: Final = "gpt-under-test"
+_NO_TRANSPORTS: Final = cast(Transport, None)
 TIMEOUT: Final = 10.0
 INTERVAL: Final = 2.0
 
@@ -156,3 +158,10 @@ class TestReplicasFor:
             replica_urls=("http://pod-1", "http://pod-2"),
         )
         assert set(client.replicas_for("/v1/mcp/server/abc")) == {"http://pod-1", "http://pod-2"}
+
+    def test_a_route_no_replica_serves_is_refused_rather_than_read_back_vacuously(self) -> None:
+        """A read-back over zero replicas would satisfy every predicate and assert
+        nothing, so asking for one fails instead of passing silently."""
+        client: Final = ProxyClient(transport=_NO_TRANSPORTS, replicas={}, control_replicas={})
+        with pytest.raises(AssertionError, match="no replica is configured"):
+            _ = client.replicas_for("/v1/models")