diff --git a/backend/app/remote_sub_agent/providers/gemini_agents.py b/backend/app/remote_sub_agent/providers/gemini_agents.py
index 3f2bd96d..06b86f22 100644
--- a/backend/app/remote_sub_agent/providers/gemini_agents.py
+++ b/backend/app/remote_sub_agent/providers/gemini_agents.py
@@ -31,7 +31,7 @@ from app.remote_sub_agent.types import (
 logger = logging.getLogger(__name__)
 
 _DEFAULT_BASE_URL = "https://generativelanguage.googleapis.com/v1beta"
-_DEFAULT_AGENT = "waverunner"
+_DEFAULT_AGENT = ""
 _TERMINAL_SUCCESS_STATUSES = {"completed"}
 _TERMINAL_FAILURE_STATUSES = {"failed", "cancelled", "expired", "incomplete"}
 _UNSUPPORTED_ACTION_STATUSES = {"requires_action"}
diff --git a/backend/tests/app/controller/test_remote_sub_agent_controller.py b/backend/tests/app/controller/test_remote_sub_agent_controller.py
index d5c94517..21bca142 100644
--- a/backend/tests/app/controller/test_remote_sub_agent_controller.py
+++ b/backend/tests/app/controller/test_remote_sub_agent_controller.py
@@ -29,7 +29,7 @@ async def test_validate_remote_sub_agent_rejects_missing_fields():
             provider="gemini_agents",
             api_key="",
             base_url="https://example.test/v1beta",
-            agent_name="waverunner",
+            agent_name="antigravity-preview-05-2026",
         )
     )
 
@@ -61,7 +61,7 @@ async def test_validate_remote_sub_agent_success(monkeypatch):
             provider="gemini_agents",
             api_key=" test-key ",
             base_url=" https://example.test/v1beta ",
-            agent_name=" waverunner ",
+            agent_name=" antigravity-preview-05-2026 ",
             timeout_seconds=12,
         )
     )
@@ -76,7 +76,7 @@ async def test_validate_remote_sub_agent_success(monkeypatch):
         "gemini_agents": {
             "api_key": "test-key",
             "base_url": "https://example.test/v1beta",
-            "agent_name": "waverunner",
+            "agent_name": "antigravity-preview-05-2026",
         },
     }
     assert seen["timeout"] == 12
@@ -98,7 +98,7 @@ async def test_validate_remote_sub_agent_failure(monkeypatch):
             provider="gemini_agents",
             api_key="bad-key",
             base_url="https://example.test/v1beta",
-            agent_name="waverunner",
+            agent_name="antigravity-preview-05-2026",
         )
     )
 
diff --git a/backend/tests/app/remote_sub_agent/test_gemini_agents_provider.py b/backend/tests/app/remote_sub_agent/test_gemini_agents_provider.py
index 221ed3ff..1bdfa450 100644
--- a/backend/tests/app/remote_sub_agent/test_gemini_agents_provider.py
+++ b/backend/tests/app/remote_sub_agent/test_gemini_agents_provider.py
@@ -48,7 +48,7 @@ async def test_provider_posts_agent_interaction():
             200,
             json={
                 "id": "interaction-1",
-                "agent": "waverunner",
+                "agent": "antigravity-preview-05-2026",
                 "environment_id": "env-1",
                 "status": "completed",
                 "outputs": [{"type": "text", "text": "done"}],
@@ -58,7 +58,7 @@ async def test_provider_posts_agent_interaction():
 
     provider = GeminiAgentsProvider(
         api_key="test-key",
-        agent_name="waverunner",
+        agent_name="antigravity-preview-05-2026",
         base_url="https://example.test/v1beta",
         transport=httpx.MockTransport(handler),
     )
@@ -77,7 +77,7 @@ async def test_provider_posts_agent_interaction():
 
     body = seen["body"]
     assert isinstance(body, dict)
-    assert body["agent"] == "waverunner"
+    assert body["agent"] == "antigravity-preview-05-2026"
     assert body["input"] == [{"type": "text", "text": "research this"}]
     assert body["stream"] is False
     assert body["environment"] == {"enabled": True}
@@ -102,7 +102,7 @@ async def test_provider_validation_posts_background_probe():
             200,
             json={
                 "id": "interaction-validation",
-                "agent": "waverunner",
+                "agent": "antigravity-preview-05-2026",
                 "environment_id": "env-validation",
                 "status": "in_progress",
             },
@@ -110,7 +110,7 @@ async def test_provider_validation_posts_background_probe():
 
     provider = GeminiAgentsProvider(
         api_key="test-key",
-        agent_name="waverunner",
+        agent_name="antigravity-preview-05-2026",
         base_url="https://example.test/v1beta",
         transport=httpx.MockTransport(handler),
     )
@@ -119,7 +119,7 @@ async def test_provider_validation_posts_background_probe():
 
     body = seen["body"]
     assert isinstance(body, dict)
-    assert body["agent"] == "waverunner"
+    assert body["agent"] == "antigravity-preview-05-2026"
     assert body["stream"] is False
     assert body["background"] is True
     assert body["environment"] == {"enabled": True}
@@ -148,14 +148,14 @@ async def test_provider_validation_falls_back_without_background():
             200,
             json={
                 "id": "interaction-validation",
-                "agent": "waverunner",
+                "agent": "antigravity-preview-05-2026",
                 "status": "completed",
             },
         )
 
     provider = GeminiAgentsProvider(
         api_key="test-key",
-        agent_name="waverunner",
+        agent_name="antigravity-preview-05-2026",
         base_url="https://example.test/v1beta",
         transport=httpx.MockTransport(handler),
     )
@@ -178,7 +178,7 @@ async def test_provider_uses_configured_agent_over_display_name():
             200,
             json={
                 "id": "interaction-1",
-                "agent": "waverunner",
+                "agent": "antigravity-preview-05-2026",
                 "status": "completed",
                 "outputs": [{"type": "text", "text": "done"}],
             },
@@ -186,7 +186,7 @@ async def test_provider_uses_configured_agent_over_display_name():
 
     provider = GeminiAgentsProvider(
         api_key="test-key",
-        agent_name="waverunner",
+        agent_name="antigravity-preview-05-2026",
         base_url="https://example.test/v1beta",
         transport=httpx.MockTransport(handler),
     )
@@ -205,7 +205,7 @@ async def test_provider_uses_configured_agent_over_display_name():
 
     body = seen["body"]
     assert isinstance(body, dict)
-    assert body["agent"] == "waverunner"
+    assert body["agent"] == "antigravity-preview-05-2026"
     assert events[-1].content == "done"
 
 
@@ -216,7 +216,7 @@ async def test_provider_concatenates_chunked_outputs_without_extra_newlines():
             200,
             json={
                 "id": "interaction-1",
-                "agent": "waverunner",
+                "agent": "antigravity-preview-05-2026",
                 "status": "completed",
                 "outputs": [
                     {"type": "text", "text": "sha256sum orders"},
@@ -229,7 +229,7 @@ async def test_provider_concatenates_chunked_outputs_without_extra_newlines():
 
     provider = GeminiAgentsProvider(
         api_key="test-key",
-        agent_name="waverunner",
+        agent_name="antigravity-preview-05-2026",
         base_url="https://example.test/v1beta",
         transport=httpx.MockTransport(handler),
     )
@@ -257,7 +257,7 @@ async def test_provider_merges_system_instruction_for_agent():
             200,
             json={
                 "id": "interaction-1",
-                "agent": "waverunner",
+                "agent": "antigravity-preview-05-2026",
                 "status": "completed",
                 "outputs": [{"type": "text", "text": "done"}],
             },
@@ -265,7 +265,7 @@ async def test_provider_merges_system_instruction_for_agent():
 
     provider = GeminiAgentsProvider(
         api_key="test-key",
-        agent_name="waverunner",
+        agent_name="antigravity-preview-05-2026",
         base_url="https://example.test/v1beta",
         transport=httpx.MockTransport(handler),
     )
@@ -302,7 +302,7 @@ async def test_provider_polls_background_agent_until_completed():
                 200,
                 json={
                     "id": "interaction-1",
-                    "agent": "waverunner",
+                    "agent": "antigravity-preview-05-2026",
                     "status": "in_progress",
                 },
             )
@@ -310,7 +310,7 @@ async def test_provider_polls_background_agent_until_completed():
             200,
             json={
                 "id": "interaction-1",
-                "agent": "waverunner",
+                "agent": "antigravity-preview-05-2026",
                 "status": "completed",
                 "outputs": [{"type": "text", "text": "done"}],
                 "usage": {"total_tokens": 42},
@@ -319,7 +319,7 @@ async def test_provider_polls_background_agent_until_completed():
 
     provider = GeminiAgentsProvider(
         api_key="test-key",
-        agent_name="waverunner",
+        agent_name="antigravity-preview-05-2026",
         base_url="https://example.test/v1beta",
         poll_interval_seconds=0,
         transport=httpx.MockTransport(handler),
diff --git a/backend/tests/app/remote_sub_agent/test_provider_registry.py b/backend/tests/app/remote_sub_agent/test_provider_registry.py
index f48a2aef..7594d8c3 100644
--- a/backend/tests/app/remote_sub_agent/test_provider_registry.py
+++ b/backend/tests/app/remote_sub_agent/test_provider_registry.py
@@ -32,7 +32,7 @@ def _config() -> dict:
         "gemini_agents": {
             "api_key": "test-key",
             "base_url": "https://example.test/v1beta",
-            "agent_name": "waverunner",
+            "agent_name": "antigravity-preview-05-2026",
             "max_wall_time_seconds": 900,
             "poll_interval_seconds": 7,
         },
@@ -62,7 +62,7 @@ def test_registry_builds_gemini_provider_from_provider_config():
     assert provider.name == "gemini_agents"
     assert provider.api_key == "test-key"
     assert provider.base_url == "https://example.test/v1beta"
-    assert provider.agent_name == "waverunner"
+    assert provider.agent_name == "antigravity-preview-05-2026"
     assert provider.poll_interval_seconds == 7
 
 
diff --git a/backend/tests/app/remote_sub_agent/test_toolkit_config.py b/backend/tests/app/remote_sub_agent/test_toolkit_config.py
index 545aa304..548c4745 100644
--- a/backend/tests/app/remote_sub_agent/test_toolkit_config.py
+++ b/backend/tests/app/remote_sub_agent/test_toolkit_config.py
@@ -31,7 +31,7 @@ def _valid_config() -> dict:
         "gemini_agents": {
             "api_key": "test-key",
             "base_url": "https://generativelanguage.googleapis.com/v1beta",
-            "agent_name": "waverunner",
+            "agent_name": "antigravity-preview-05-2026",
             "max_wall_time_seconds": 900,
             "poll_interval_seconds": 5,
         },
@@ -58,7 +58,7 @@ async def test_toolkit_returns_message_when_config_is_incomplete():
             "gemini_agents": {
                 "api_key": "",
                 "base_url": "https://generativelanguage.googleapis.com/v1beta",
-                "agent_name": "waverunner",
+                "agent_name": "antigravity-preview-05-2026",
             },
         },
     )
diff --git a/server/app/model/remote_sub_agent/provider.py b/server/app/model/remote_sub_agent/provider.py
index 9fca7e31..cd1b5365 100644
--- a/server/app/model/remote_sub_agent/provider.py
+++ b/server/app/model/remote_sub_agent/provider.py
@@ -44,15 +44,18 @@ class RemoteSubAgentProviderIn(BaseModel):
     config: dict | None = None
 
     @model_validator(mode="after")
-    def validate_enabled_config(self):
-        if self.enabled and (
+    def validate_provider_config(self):
+        if not self.provider_name.strip():
+            raise ValueError("Remote sub agent provider requires provider_name.")
+
+        if (
             not self.api_key.strip()
             or not self.endpoint_url.strip()
             or not self.agent_name.strip()
         ):
             raise ValueError(
-                "Enabled remote sub agent provider requires api_key, "
-                "endpoint_url, and agent_name."
+                "Remote sub agent provider requires api_key, endpoint_url, "
+                "and agent_name."
             )
         return self
 
diff --git a/server/tests/test_remote_sub_agent_provider.py b/server/tests/test_remote_sub_agent_provider.py
index 023eb71f..47957ac4 100644
--- a/server/tests/test_remote_sub_agent_provider.py
+++ b/server/tests/test_remote_sub_agent_provider.py
@@ -21,10 +21,24 @@ from app.model.remote_sub_agent.provider import RemoteSubAgentProviderIn
 
 
 class TestRemoteSubAgentProviderSchema:
-    def test_disabled_provider_allows_incomplete_credentials(self):
+    def test_disabled_provider_requires_credentials(self):
+        with pytest.raises(ValidationError):
+            RemoteSubAgentProviderIn(
+                provider_name="gemini_agents",
+                enabled=False,
+            )
+
+    def test_disabled_provider_accepts_agent_configuration(self):
         config = RemoteSubAgentProviderIn(
             provider_name="gemini_agents",
             enabled=False,
+            api_key="test-key",
+            endpoint_url="https://generativelanguage.googleapis.com/v1beta",
+            agent_name="antigravity-preview-05-2026",
+            config={
+                "max_wall_time_seconds": 900,
+                "poll_interval_seconds": 5,
+            },
         )
 
         assert config.provider_name == "gemini_agents"
@@ -47,7 +61,7 @@ class TestRemoteSubAgentProviderSchema:
             enabled=True,
             api_key="test-key",
             endpoint_url="https://generativelanguage.googleapis.com/v1beta",
-            agent_name="waverunner",
+            agent_name="antigravity-preview-05-2026",
             config={
                 "max_wall_time_seconds": 900,
                 "poll_interval_seconds": 5,
diff --git a/src/i18n/locales/ar/setting.json b/src/i18n/locales/ar/setting.json
index 7acfee52..c433e398 100644
--- a/src/i18n/locales/ar/setting.json
+++ b/src/i18n/locales/ar/setting.json
@@ -178,6 +178,15 @@
   "models-default-setting-title": "الإعداد الافتراضي",
   "models-default-setting-description": "اختر أحد النماذج المكوّنة ليكون النموذج الافتراضي لـ Eigent، وسيتم تطبيقه عالميًا عبر مساحة العمل الخاصة بك.",
   "models-configuration": "التكوين",
+  "sub-agents": "الوكلاء الفرعيون",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "فوّض المهام المناسبة إلى صندوق عزل مُدار لوكيل بعيد.",
+  "agent-provider": "موفّر الوكيل",
+  "agent-id": "معرّف الوكيل",
+  "max-wall-time-seconds": "الحد الأقصى لوقت التشغيل (بالثواني)",
+  "poll-interval-seconds": "فاصل الاستعلام (بالثواني)",
+  "remote-sub-agent-required-fields": "API Key و API Host و Agent ID مطلوبة عند تفعيل Sub Agent.",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/de/setting.json b/src/i18n/locales/de/setting.json
index bcd167c8..957ff6cc 100644
--- a/src/i18n/locales/de/setting.json
+++ b/src/i18n/locales/de/setting.json
@@ -238,6 +238,15 @@
   "models-default-setting-title": "Standard-Einstellung",
   "models-default-setting-description": "Wähle eines deiner konfigurierten Modelle als Standardmodell für Eigent. Es wird global in deinem Arbeitsbereich angewendet.",
   "models-configuration": "Konfiguration",
+  "sub-agents": "Sub-Agents",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "Delegiere geeignete Aufgaben an eine verwaltete Remote-Agent-Sandbox.",
+  "agent-provider": "Agent-Anbieter",
+  "agent-id": "Agent-ID",
+  "max-wall-time-seconds": "Max. Laufzeit (Sekunden)",
+  "poll-interval-seconds": "Abfrageintervall (Sekunden)",
+  "remote-sub-agent-required-fields": "API-Schlüssel, API-Host und Agent-ID sind erforderlich, wenn Sub Agent aktiviert ist.",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/en-us/setting.json b/src/i18n/locales/en-us/setting.json
index 31b63dd5..8464ac86 100644
--- a/src/i18n/locales/en-us/setting.json
+++ b/src/i18n/locales/en-us/setting.json
@@ -209,7 +209,7 @@
   "sub-agents": "Sub Agents",
   "gemini-agent": "Gemini Agents API",
   "gemini-remote-sub-agent": "Gemini Agents API",
-  "remote-sub-agent-description": "Delegate suitable tasks to a managed Waverunner-compatible remote agent sandbox.",
+  "remote-sub-agent-description": "Delegate suitable tasks to a managed remote agent sandbox.",
   "agent-provider": "Agent Provider",
   "agent-id": "Agent ID",
   "max-wall-time-seconds": "Max Wall Time (Seconds)",
diff --git a/src/i18n/locales/es/setting.json b/src/i18n/locales/es/setting.json
index 4161e533..240c9096 100644
--- a/src/i18n/locales/es/setting.json
+++ b/src/i18n/locales/es/setting.json
@@ -238,6 +238,15 @@
   "models-default-setting-title": "Configuración predeterminada",
   "models-default-setting-description": "Elige uno de tus modelos configurados como modelo predeterminado para Eigent. Se aplicará globalmente en tu espacio de trabajo.",
   "models-configuration": "Configuración",
+  "sub-agents": "Subagentes",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "Delega tareas adecuadas a un sandbox de agente remoto administrado.",
+  "agent-provider": "Proveedor de agente",
+  "agent-id": "ID de agente",
+  "max-wall-time-seconds": "Tiempo máximo de ejecución (segundos)",
+  "poll-interval-seconds": "Intervalo de sondeo (segundos)",
+  "remote-sub-agent-required-fields": "API Key, API Host y Agent ID son obligatorios cuando Sub Agent está habilitado.",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/fr/setting.json b/src/i18n/locales/fr/setting.json
index 887b22c0..8ab1b1c0 100644
--- a/src/i18n/locales/fr/setting.json
+++ b/src/i18n/locales/fr/setting.json
@@ -221,6 +221,15 @@
   "models-default-setting-title": "Paramètre par défaut",
   "models-default-setting-description": "Choisissez l'un de vos modèles configurés comme modèle par défaut pour Eigent. Il sera appliqué globalement dans votre espace de travail.",
   "models-configuration": "Configuration",
+  "sub-agents": "Sous-agents",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "Déléguez les tâches adaptées à un bac à sable d'agent distant géré.",
+  "agent-provider": "Fournisseur d'agent",
+  "agent-id": "ID de l'agent",
+  "max-wall-time-seconds": "Temps d'exécution maximal (secondes)",
+  "poll-interval-seconds": "Intervalle d'interrogation (secondes)",
+  "remote-sub-agent-required-fields": "La clé API, l'hôte API et l'ID de l'agent sont requis lorsque Sub Agent est activé.",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/it/setting.json b/src/i18n/locales/it/setting.json
index 169285d1..d5a225ef 100644
--- a/src/i18n/locales/it/setting.json
+++ b/src/i18n/locales/it/setting.json
@@ -238,6 +238,15 @@
   "models-default-setting-title": "Impostazione predefinita",
   "models-default-setting-description": "Seleziona uno dei modelli configurati come modello predefinito per Eigent. Verrà applicato globalmente nel tuo spazio di lavoro.",
   "models-configuration": "Configurazione",
+  "sub-agents": "Sub-agent",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "Delega le attività adatte a una sandbox di agent remoto gestita.",
+  "agent-provider": "Provider agent",
+  "agent-id": "ID agent",
+  "max-wall-time-seconds": "Tempo massimo di esecuzione (secondi)",
+  "poll-interval-seconds": "Intervallo di polling (secondi)",
+  "remote-sub-agent-required-fields": "API Key, API Host e Agent ID sono obbligatori quando Sub Agent è abilitato.",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/ja/setting.json b/src/i18n/locales/ja/setting.json
index 70b6d2ce..c5c3bf52 100644
--- a/src/i18n/locales/ja/setting.json
+++ b/src/i18n/locales/ja/setting.json
@@ -239,6 +239,15 @@
   "models-default-setting-title": "デフォルト設定",
   "models-default-setting-description": "設定済みモデルの中から、Eigent のデフォルトモデルを1つ選択します。ワークスペース全体にグローバルに適用されます。",
   "models-configuration": "構成",
+  "sub-agents": "サブエージェント",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "適したタスクを管理されたリモートエージェントのサンドボックスに委任します。",
+  "agent-provider": "エージェントプロバイダー",
+  "agent-id": "エージェント ID",
+  "max-wall-time-seconds": "最大実行時間（秒）",
+  "poll-interval-seconds": "ポーリング間隔（秒）",
+  "remote-sub-agent-required-fields": "Sub Agent を有効にするには、API Key、API Host、Agent ID が必要です。",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/ko/setting.json b/src/i18n/locales/ko/setting.json
index 73319eaf..38639223 100644
--- a/src/i18n/locales/ko/setting.json
+++ b/src/i18n/locales/ko/setting.json
@@ -239,6 +239,15 @@
   "models-default-setting-title": "기본 설정",
   "models-default-setting-description": "구성된 모델 중 하나를 Eigent의 기본 모델로 선택하세요. 워크스페이스 전체에 전역으로 적용됩니다.",
   "models-configuration": "구성",
+  "sub-agents": "서브 에이전트",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "적합한 작업을 관리형 원격 에이전트 샌드박스에 위임합니다.",
+  "agent-provider": "에이전트 제공자",
+  "agent-id": "에이전트 ID",
+  "max-wall-time-seconds": "최대 실행 시간(초)",
+  "poll-interval-seconds": "폴링 간격(초)",
+  "remote-sub-agent-required-fields": "Sub Agent를 활성화하려면 API Key, API Host, Agent ID가 필요합니다.",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/ru/setting.json b/src/i18n/locales/ru/setting.json
index 0e6883fa..e4844c3a 100644
--- a/src/i18n/locales/ru/setting.json
+++ b/src/i18n/locales/ru/setting.json
@@ -238,6 +238,15 @@
   "models-default-setting-title": "Настройка по умолчанию",
   "models-default-setting-description": "Выберите одну из настроенных моделей как модель по умолчанию для Eigent. Она будет применяться глобально во всём рабочем пространстве.",
   "models-configuration": "Конфигурация",
+  "sub-agents": "Суб-агенты",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "Делегируйте подходящие задачи управляемой песочнице удалённого агента.",
+  "agent-provider": "Поставщик агента",
+  "agent-id": "ID агента",
+  "max-wall-time-seconds": "Макс. время выполнения (секунды)",
+  "poll-interval-seconds": "Интервал опроса (секунды)",
+  "remote-sub-agent-required-fields": "API Key, API Host и Agent ID обязательны, когда Sub Agent включён.",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/i18n/locales/zh-Hans/setting.json b/src/i18n/locales/zh-Hans/setting.json
index 6cc90ac2..7c5d87ab 100644
--- a/src/i18n/locales/zh-Hans/setting.json
+++ b/src/i18n/locales/zh-Hans/setting.json
@@ -199,7 +199,7 @@
   "sub-agents": "Sub Agents",
   "gemini-agent": "Gemini Agents API",
   "gemini-remote-sub-agent": "Gemini Agents API",
-  "remote-sub-agent-description": "把适合远程执行的任务委托给 Waverunner 兼容的托管智能体沙盒。",
+  "remote-sub-agent-description": "把适合远程执行的任务委托给托管远程智能体沙盒。",
   "agent-provider": "Agent Provider",
   "agent-id": "Agent ID",
   "max-wall-time-seconds": "最长运行时间（秒）",
diff --git a/src/i18n/locales/zh-Hant/setting.json b/src/i18n/locales/zh-Hant/setting.json
index e68af641..a229d1b1 100644
--- a/src/i18n/locales/zh-Hant/setting.json
+++ b/src/i18n/locales/zh-Hant/setting.json
@@ -167,6 +167,15 @@
   "models-default-setting-title": "預設設定",
   "models-default-setting-description": "從已配置的模型中選擇一個作為 Eigent 的預設模型，它將全域套用於您的工作區。",
   "models-configuration": "配置",
+  "sub-agents": "Sub Agents",
+  "gemini-agent": "Gemini Agents API",
+  "gemini-remote-sub-agent": "Gemini Agents API",
+  "remote-sub-agent-description": "把適合遠端執行的任務委託給託管遠端智能體沙盒。",
+  "agent-provider": "Agent Provider",
+  "agent-id": "Agent ID",
+  "max-wall-time-seconds": "最長執行時間（秒）",
+  "poll-interval-seconds": "輪詢間隔（秒）",
+  "remote-sub-agent-required-fields": "啟用 Sub Agent 時，需要填寫 API Key、API Host 和 Agent ID。",
 
   "gemini-3-pro-preview-name": "Gemini 3 Pro Preview",
   "gemini-3.1-pro-preview-name": "Gemini 3.1 Pro Preview",
diff --git a/src/lib/remoteSubAgent.ts b/src/lib/remoteSubAgent.ts
index 051d165b..10a9c440 100644
--- a/src/lib/remoteSubAgent.ts
+++ b/src/lib/remoteSubAgent.ts
@@ -16,7 +16,7 @@ export const REMOTE_SUB_AGENT_PROVIDER = 'gemini_agents';
 export const REMOTE_SUB_AGENT_PROVIDER_ID = REMOTE_SUB_AGENT_PROVIDER;
 export const REMOTE_SUB_AGENT_DEFAULT_BASE_URL =
   'https://generativelanguage.googleapis.com/v1beta';
-export const REMOTE_SUB_AGENT_DEFAULT_AGENT = 'waverunner';
+export const REMOTE_SUB_AGENT_DEFAULT_AGENT = '';
 export const REMOTE_SUB_AGENT_DEFAULT_MAX_WALL_TIME_SECONDS = '900';
 export const REMOTE_SUB_AGENT_DEFAULT_POLL_INTERVAL_SECONDS = '5';
 
@@ -101,6 +101,12 @@ export function toRemoteSubAgentProviderPayload(form: RemoteSubAgentFormState) {
   const agentName = form.agentName.trim();
   const maxWallTimeSeconds = Number(form.maxWallTimeSeconds);
   const pollIntervalSeconds = Number(form.pollIntervalSeconds);
+  const fallbackMaxWallTimeSeconds = Number(
+    REMOTE_SUB_AGENT_DEFAULT_MAX_WALL_TIME_SECONDS
+  );
+  const fallbackPollIntervalSeconds = Number(
+    REMOTE_SUB_AGENT_DEFAULT_POLL_INTERVAL_SECONDS
+  );
 
   return {
     provider_name: REMOTE_SUB_AGENT_PROVIDER_ID,
@@ -110,12 +116,14 @@ export function toRemoteSubAgentProviderPayload(form: RemoteSubAgentFormState) {
     agent_name: agentName,
     model_name: '',
     config: {
-      max_wall_time_seconds: Number.isFinite(maxWallTimeSeconds)
-        ? maxWallTimeSeconds
-        : Number(REMOTE_SUB_AGENT_DEFAULT_MAX_WALL_TIME_SECONDS),
-      poll_interval_seconds: Number.isFinite(pollIntervalSeconds)
-        ? pollIntervalSeconds
-        : Number(REMOTE_SUB_AGENT_DEFAULT_POLL_INTERVAL_SECONDS),
+      max_wall_time_seconds:
+        Number.isFinite(maxWallTimeSeconds) && maxWallTimeSeconds > 0
+          ? maxWallTimeSeconds
+          : fallbackMaxWallTimeSeconds,
+      poll_interval_seconds:
+        Number.isFinite(pollIntervalSeconds) && pollIntervalSeconds > 0
+          ? pollIntervalSeconds
+          : fallbackPollIntervalSeconds,
     },
   };
 }
diff --git a/src/pages/Agents/SubAgents.tsx b/src/pages/Agents/SubAgents.tsx
index 37b6aa2e..857eda4f 100644
--- a/src/pages/Agents/SubAgents.tsx
+++ b/src/pages/Agents/SubAgents.tsx
@@ -75,10 +75,22 @@ export default function SubAgents() {
     return t('setting.validate-failed');
   };
 
-  const getRemoteSubAgentRequiredError = (form: RemoteSubAgentFormState) => {
+  const getRemoteSubAgentRequiredError = (
+    form: RemoteSubAgentFormState,
+    requireFields = form.enabled
+  ) => {
+    const maxWallTimeSeconds = Number(form.maxWallTimeSeconds.trim());
+    const pollIntervalSeconds = Number(form.pollIntervalSeconds.trim());
+
     if (
-      form.enabled &&
-      (!form.apiKey.trim() || !form.baseUrl.trim() || !form.agentName.trim())
+      requireFields &&
+      (!form.apiKey.trim() ||
+        !form.baseUrl.trim() ||
+        !form.agentName.trim() ||
+        !Number.isFinite(maxWallTimeSeconds) ||
+        maxWallTimeSeconds <= 0 ||
+        !Number.isFinite(pollIntervalSeconds) ||
+        pollIntervalSeconds <= 0)
     ) {
       return t('setting.remote-sub-agent-required-fields');
     }
@@ -105,8 +117,17 @@ export default function SubAgents() {
     });
   };
 
-  const persistRemoteSubAgentForm = async (form: RemoteSubAgentFormState) => {
-    const requiredError = getRemoteSubAgentRequiredError(form);
+  const persistRemoteSubAgentForm = async (
+    form: RemoteSubAgentFormState,
+    {
+      requireFields = form.enabled,
+      validateConnection = form.enabled,
+    }: {
+      requireFields?: boolean;
+      validateConnection?: boolean;
+    } = {}
+  ) => {
+    const requiredError = getRemoteSubAgentRequiredError(form, requireFields);
     if (requiredError) {
       setRemoteSubAgentError(requiredError);
       toast.error(requiredError);
@@ -116,7 +137,7 @@ export default function SubAgents() {
     setRemoteSubAgentSaving(true);
     setRemoteSubAgentError(null);
     try {
-      if (form.enabled) {
+      if (validateConnection) {
         await validateRemoteSubAgentConfig(form);
       }
 
@@ -145,7 +166,10 @@ export default function SubAgents() {
   };
 
   const handleRemoteSubAgentSave = async () => {
-    await persistRemoteSubAgentForm(remoteSubAgentForm);
+    await persistRemoteSubAgentForm(remoteSubAgentForm, {
+      requireFields: true,
+      validateConnection: true,
+    });
   };
 
   const handleRemoteSubAgentToggle = async (checked: boolean) => {
@@ -155,7 +179,13 @@ export default function SubAgents() {
       enabled: checked,
     };
 
-    const requiredError = getRemoteSubAgentRequiredError(nextForm);
+    if (!checked && !remoteSubAgentForm.provider_id) {
+      setRemoteSubAgentForm(nextForm);
+      setRemoteSubAgentError(null);
+      return;
+    }
+
+    const requiredError = getRemoteSubAgentRequiredError(nextForm, checked);
     if (requiredError) {
       setRemoteSubAgentError(requiredError);
       toast.error(requiredError);
@@ -163,7 +193,10 @@ export default function SubAgents() {
     }
 
     setRemoteSubAgentForm(nextForm);
-    const saved = await persistRemoteSubAgentForm(nextForm);
+    const saved = await persistRemoteSubAgentForm(nextForm, {
+      requireFields: checked,
+      validateConnection: checked,
+    });
     if (!saved) {
       setRemoteSubAgentForm(previousForm);
     }