diff --git a/studio/backend/models/inference.py b/studio/backend/models/inference.py
index 66b599962b..df57791eb9 100644
--- a/studio/backend/models/inference.py
+++ b/studio/backend/models/inference.py
@@ -374,7 +374,9 @@ class ChatMessage(BaseModel):
             if self.content is None:
                 raise ValueError("tool messages require content")
             if not self.tool_call_id:
-                raise ValueError("tool messages require tool_call_id")
+                raise ValueError(
+                    'role="tool" messages require "tool_call_id" per the OpenAI spec.'
+                )
         else:
             if self.content is None:
                 raise ValueError(f"{self.role} messages require content")
diff --git a/studio/backend/tests/test_openai_tool_passthrough.py b/studio/backend/tests/test_openai_tool_passthrough.py
index 1c0dec1264..056b1a62a2 100644
--- a/studio/backend/tests/test_openai_tool_passthrough.py
+++ b/studio/backend/tests/test_openai_tool_passthrough.py
@@ -111,9 +111,31 @@ class TestChatMessageToolRoles:
             ChatMessage(role = "function", content = "x")
 
     def test_content_absent_defaults_to_none(self):
-        msg = ChatMessage(role = "assistant")
+        msg = ChatMessage(
+            role = "assistant",
+            tool_calls = [
+                {"id": "c1", "type": "function", "function": {"name": "f", "arguments": "{}"}}
+            ],
+        )
         assert msg.content is None
 
+    def test_tool_role_missing_tool_call_id_rejected(self):
+        # Per OpenAI spec, role="tool" messages must carry tool_call_id so
+        # upstream backends can associate the result with its prior call.
+        # Pin the boundary-level rejection so a malformed tool-result
+        # message never reaches the passthrough path.
+        with pytest.raises(ValidationError) as exc_info:
+            ChatMessage(role = "tool", content = '{"temperature": 72}')
+        assert "tool_call_id" in str(exc_info.value)
+
+    def test_tool_role_empty_tool_call_id_rejected(self):
+        with pytest.raises(ValidationError):
+            ChatMessage(
+                role = "tool",
+                tool_call_id = "",
+                content = '{"temperature": 72}',
+            )
+
 
 # =====================================================================
 # ChatCompletionRequest — standard OpenAI tool fields
diff --git a/studio/frontend/src/components/app-sidebar.tsx b/studio/frontend/src/components/app-sidebar.tsx
index 8264f329a3..329175fa9c 100644
--- a/studio/frontend/src/components/app-sidebar.tsx
+++ b/studio/frontend/src/components/app-sidebar.tsx
@@ -330,7 +330,7 @@ export function AppSidebar() {
             <SidebarMenu>
               <NavItem
                 icon={ZapIcon}
-                label="Studio"
+                label="Train"
                 active={pathname === "/studio" || pathname.startsWith("/studio/")}
                 disabled={chatOnly}
                 onClick={() => {
@@ -511,7 +511,7 @@ export function AppSidebar() {
                   />
                   <div className="flex flex-col gap-0.5 leading-none group-data-[collapsible=icon]:hidden">
                     <span className="truncate text-sm font-semibold">Unsloth</span>
-                    <span className="truncate text-[11px] text-muted-foreground">Studio</span>
+                    <span className="truncate text-[11px] text-muted-foreground">Train</span>
                   </div>
                   <ChevronsUpDown strokeWidth={1.25} className="ml-auto size-4 text-muted-foreground group-data-[collapsible=icon]:hidden" />
                 </SidebarMenuButton>
diff --git a/studio/frontend/src/features/onboarding/components/wizard-footer.tsx b/studio/frontend/src/features/onboarding/components/wizard-footer.tsx
index 4588c0a632..399bf115f1 100644
--- a/studio/frontend/src/features/onboarding/components/wizard-footer.tsx
+++ b/studio/frontend/src/features/onboarding/components/wizard-footer.tsx
@@ -69,7 +69,7 @@ export function WizardFooter({
                 if (currentStep === 1 && sessionStorage.getItem("unsloth_chat_only") === "1") {
                   sessionStorage.removeItem("unsloth_chat_only");
                   markOnboardingDone();
-                  window.location.assign(returnTo);
+                  window.location.assign("/chat");
                 } else {
                   nextStep();
                 }
diff --git a/studio/frontend/src/features/settings/tabs/general-tab.tsx b/studio/frontend/src/features/settings/tabs/general-tab.tsx
index a79b134e97..874508a6fb 100644
--- a/studio/frontend/src/features/settings/tabs/general-tab.tsx
+++ b/studio/frontend/src/features/settings/tabs/general-tab.tsx
@@ -12,6 +12,7 @@ import {
 } from "@/components/ui/dialog";
 import { Input } from "@/components/ui/input";
 import { Switch } from "@/components/ui/switch";
+import { usePlatformStore } from "@/config/env";
 import { resetOnboardingDone } from "@/features/auth";
 import { useChatRuntimeStore } from "@/features/chat/stores/chat-runtime-store";
 import { useSettingsDialogStore } from "@/features/settings";
@@ -95,6 +96,7 @@ export function GeneralTab() {
   const setHfToken = useChatRuntimeStore((s) => s.setHfToken);
   const autoTitle = useChatRuntimeStore((s) => s.autoTitle);
   const setAutoTitle = useChatRuntimeStore((s) => s.setAutoTitle);
+  const chatOnly = usePlatformStore((s) => s.chatOnly);
   const redirectTo = `${pathname}${search}`;
 
   const [draftToken, setDraftToken] = useState(hfToken ?? "");
@@ -170,24 +172,26 @@ export function GeneralTab() {
         </SettingsRow>
       </SettingsSection>
 
-      <SettingsSection title="Getting started">
-        <SettingsRow
-          label="Start onboarding"
-          description="Open the setup wizard again without changing your account."
-        >
-          <Button
-            variant="outline"
-            size="sm"
-            onClick={() => {
-              resetOnboardingDone();
-              closeDialog();
-              navigate({ to: "/onboarding", search: { redirectTo } });
-            }}
+      {!chatOnly && (
+        <SettingsSection title="Getting started">
+          <SettingsRow
+            label="Start onboarding"
+            description="Open the setup wizard again without changing your account."
           >
-            Start onboarding
-          </Button>
-        </SettingsRow>
-      </SettingsSection>
+            <Button
+              variant="outline"
+              size="sm"
+              onClick={() => {
+                resetOnboardingDone();
+                closeDialog();
+                navigate({ to: "/onboarding", search: { redirectTo } });
+              }}
+            >
+              Start onboarding
+            </Button>
+          </SettingsRow>
+        </SettingsSection>
+      )}
 
       <SettingsSection title="Danger zone">
         <SettingsRow