diff --git a/agentex-ui/lib/task-utils.test.ts b/agentex-ui/lib/task-utils.test.ts
index 16e02a41..a8a10578 100644
--- a/agentex-ui/lib/task-utils.test.ts
+++ b/agentex-ui/lib/task-utils.test.ts
@@ -5,69 +5,49 @@ import { createTaskName } from '@/lib/task-utils';
 import type { TaskListResponse } from 'agentex/resources';
 
 describe('createTaskName', () => {
-  it('returns description when params.description is a string', () => {
+  it('returns task_metadata.display_name when present', () => {
     const task = {
       id: '123',
-      params: {
-        description: 'Test task description',
-      },
-    } as TaskListResponse.TaskListResponseItem;
-
-    expect(createTaskName(task)).toBe('Test task description');
-  });
-
-  it('returns "Unnamed task" when params.description is missing', () => {
-    const task = {
-      params: {},
-    } as TaskListResponse.TaskListResponseItem;
-
-    expect(createTaskName(task)).toBe('Unnamed task');
-  });
-
-  it('returns "Unnamed task" when params is missing', () => {
-    const task = {} as TaskListResponse.TaskListResponseItem;
+      task_metadata: { display_name: 'My task' },
+    } as unknown as TaskListResponse.TaskListResponseItem;
 
-    expect(createTaskName(task)).toBe('Unnamed task');
+    expect(createTaskName(task)).toBe('My task');
   });
 
-  it('returns "Unnamed task" when params.description is not a string', () => {
+  it('strips the legacy scheduled-message prefix from display_name', () => {
     const task = {
-      params: {
-        description: 123,
+      id: '123',
+      task_metadata: {
+        display_name: 'Scheduled Message: Daily digest',
+        schedule_id: 'sched-1',
       },
     } as unknown as TaskListResponse.TaskListResponseItem;
 
-    expect(createTaskName(task)).toBe('Unnamed task');
+    expect(createTaskName(task)).toBe('Daily digest');
   });
 
-  it('returns "Unnamed task" when params.description is null', () => {
+  it('falls back to the task name when there is no display_name', () => {
     const task = {
-      params: {
-        description: null,
-      },
+      id: '123',
+      name: 'my-task-name',
     } as unknown as TaskListResponse.TaskListResponseItem;
 
-    expect(createTaskName(task)).toBe('Unnamed task');
+    expect(createTaskName(task)).toBe('my-task-name');
   });
 
-  it('returns "Unnamed task" when params.description is undefined', () => {
+  it('returns "Unnamed task" when neither display_name nor name is set', () => {
     const task = {
       id: '123',
-      params: {
-        description: undefined,
-      },
-    } as TaskListResponse.TaskListResponseItem;
+    } as unknown as TaskListResponse.TaskListResponseItem;
 
     expect(createTaskName(task)).toBe('Unnamed task');
   });
 
-  it('returns "Unnamed task" for empty string description', () => {
+  it('returns "Unnamed task" when name is an empty string', () => {
     const task = {
       id: '123',
-      params: {
-        description: '',
-      },
-    } as TaskListResponse.TaskListResponseItem;
+      name: '',
+    } as unknown as TaskListResponse.TaskListResponseItem;
 
     expect(createTaskName(task)).toBe('Unnamed task');
   });
diff --git a/agentex-ui/lib/task-utils.ts b/agentex-ui/lib/task-utils.ts
index 9a6d2e7c..1e5a3e23 100644
--- a/agentex-ui/lib/task-utils.ts
+++ b/agentex-ui/lib/task-utils.ts
@@ -20,11 +20,8 @@ export function createTaskName(
     return displayName;
   }
 
-  if (
-    task?.params?.description &&
-    typeof task.params.description === 'string'
-  ) {
-    return task.params.description;
+  if (typeof task?.name === 'string' && task.name) {
+    return task.name;
   }
 
   return 'Unnamed task';
diff --git a/agentex/openapi.yaml b/agentex/openapi.yaml
index 904f1615..b8ab2b22 100644
--- a/agentex/openapi.yaml
+++ b/agentex/openapi.yaml
@@ -555,7 +555,8 @@ paths:
       tags:
       - Tasks
       summary: List Tasks
-      description: List all tasks.
+      description: List tasks. Returns a lean summary per task and omits `params`;
+        fetch GET /tasks/{task_id} for the full record including `params`.
       operationId: list_tasks_tasks_get
       parameters:
       - name: agent_id
@@ -641,7 +642,7 @@ paths:
               schema:
                 type: array
                 items:
-                  $ref: '#/components/schemas/TaskResponse'
+                  $ref: '#/components/schemas/TaskSummary'
                 title: Response List Tasks Tasks Get
         '422':
           description: Validation Error
@@ -6845,6 +6846,68 @@ components:
           title: Optional reason for the status change
       type: object
       title: TaskStatusReasonRequest
+    TaskSummary:
+      properties:
+        id:
+          type: string
+          title: Unique Task ID
+        name:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: Unique name of the task
+        status:
+          anyOf:
+          - $ref: '#/components/schemas/TaskStatus'
+          - type: 'null'
+          title: The current status of the task
+        status_reason:
+          anyOf:
+          - type: string
+          - type: 'null'
+          title: The reason for the current task status
+        created_at:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: The timestamp when the task was created
+        updated_at:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: The timestamp when the task was last updated
+        cleaned_at:
+          anyOf:
+          - type: string
+            format: date-time
+          - type: 'null'
+          title: The timestamp when the task's content was cleaned for retention compliance;
+            null when active
+        task_metadata:
+          anyOf:
+          - additionalProperties: true
+            type: object
+          - type: 'null'
+          title: Task metadata
+        agents:
+          anyOf:
+          - items:
+              $ref: '#/components/schemas/Agent'
+            type: array
+          - type: 'null'
+          title: Agents associated with this task (only populated when 'agents' view
+            is requested)
+      type: object
+      required:
+      - id
+      title: TaskSummary
+      description: 'Lean list-response shape. Omits `params` (the arbitrary create-time
+
+        payload, which can carry per-caller secrets and PII); fetch GET /tasks/{id}
+
+        for the full record.'
     TextContent:
       properties:
         type:
diff --git a/agentex/src/api/routes/tasks.py b/agentex/src/api/routes/tasks.py
index 86abb22a..6c9dab91 100644
--- a/agentex/src/api/routes/tasks.py
+++ b/agentex/src/api/routes/tasks.py
@@ -17,6 +17,7 @@
     TaskResponse,
     TaskStatus,
     TaskStatusReasonRequest,
+    TaskSummary,
     UpdateTaskRequest,
 )
 from src.domain.entities.tasks import TaskStatus as DomainTaskStatus
@@ -73,9 +74,12 @@ async def get_task_by_name(
 
 @router.get(
     "",
-    response_model=list[TaskResponse],
+    response_model=list[TaskSummary],
     summary="List Tasks",
-    description="List all tasks.",
+    description=(
+        "List tasks. Returns a lean summary per task and omits `params`; "
+        "fetch GET /tasks/{task_id} for the full record including `params`."
+    ),
 )
 async def list_tasks(
     task_use_case: DTaskUseCase,
@@ -143,7 +147,7 @@ async def list_tasks(
         order_direction=order_direction,
         relationships=relationships,
     )
-    return [TaskResponse.model_validate(task_entity) for task_entity in task_entities]
+    return [TaskSummary.model_validate(task_entity) for task_entity in task_entities]
 
 
 @router.delete(
diff --git a/agentex/src/api/schemas/tasks.py b/agentex/src/api/schemas/tasks.py
index a79d9fef..f5efaad6 100644
--- a/agentex/src/api/schemas/tasks.py
+++ b/agentex/src/api/schemas/tasks.py
@@ -74,6 +74,49 @@ class TaskResponse(Task):
     )
 
 
+class TaskSummary(BaseModel):
+    """Lean list-response shape. Omits `params` (the arbitrary create-time
+    payload, which can carry per-caller secrets and PII); fetch GET /tasks/{id}
+    for the full record."""
+
+    id: str = Field(
+        ...,
+        title="Unique Task ID",
+    )
+    name: str | None = Field(
+        None,
+        title="Unique name of the task",
+    )
+    status: TaskStatus | None = Field(
+        None,
+        title="The current status of the task",
+    )
+    status_reason: str | None = Field(
+        None,
+        title="The reason for the current task status",
+    )
+    created_at: datetime | None = Field(
+        None,
+        title="The timestamp when the task was created",
+    )
+    updated_at: datetime | None = Field(
+        None,
+        title="The timestamp when the task was last updated",
+    )
+    cleaned_at: datetime | None = Field(
+        None,
+        title="The timestamp when the task's content was cleaned for retention compliance; null when active",
+    )
+    task_metadata: dict[str, Any] | None = Field(
+        None,
+        title="Task metadata",
+    )
+    agents: list["Agent"] | None = Field(
+        default=None,
+        title="Agents associated with this task (only populated when 'agents' view is requested)",
+    )
+
+
 class UpdateTaskRequest(BaseModel):
     task_metadata: dict[str, Any] | None = Field(
         None,
diff --git a/agentex/tests/integration/api/tasks/test_tasks_api.py b/agentex/tests/integration/api/tasks/test_tasks_api.py
index bdf857bd..dbf0a1a4 100644
--- a/agentex/tests/integration/api/tasks/test_tasks_api.py
+++ b/agentex/tests/integration/api/tasks/test_tasks_api.py
@@ -141,6 +141,10 @@ async def test_list_tasks_returns_valid_structure_and_schema(
         for task in tasks:
             assert "id" in task and isinstance(task["id"], str)
 
+            # The list is a lean summary and must never carry `params` (the
+            # arbitrary create-time payload that can hold secrets/PII).
+            assert "params" not in task
+
             # Check if this is our test task
             if task["id"] == test_task.id:
                 found_test_task = True
@@ -499,32 +503,24 @@ async def test_get_task_by_name_non_existent_returns_404(self, isolated_client):
         assert response.status_code == 404
 
     #
-    async def test_list_tasks_includes_params_in_response(
+    async def test_list_tasks_omits_params_in_response(
         self, isolated_client, test_task_with_params
     ):
-        """Test that list tasks endpoint includes params field in response"""
+        """The list summary must omit `params` even when the task has them
+        (they can carry secrets/PII); fetch a single task for the full record."""
         # When - Request all tasks
         response = await isolated_client.get("/tasks")
 
-        # Then - Should succeed and include params in response
+        # Then - The task is present but its params are not serialized
         assert response.status_code == 200
         tasks = response.json()
         assert isinstance(tasks, list)
 
-        # Find our test task with params
         params_task = next(
             (task for task in tasks if task["id"] == test_task_with_params.id), None
         )
-        assert params_task is not None, "Task with params should be in the list"
-
-        # Verify params field exists and has correct structure
-        assert "params" in params_task
-        assert params_task["params"] is not None
-        assert params_task["params"]["model"] == "gpt-4"
-        assert params_task["params"]["temperature"] == 0.8
-        assert params_task["params"]["max_tokens"] == 2000
-        assert params_task["params"]["nested"]["setting"] == "value"
-        assert params_task["params"]["nested"]["numbers"] == [1, 2, 3]
+        assert params_task is not None, "Task should be in the list"
+        assert "params" not in params_task
 
     #
     async def test_get_task_by_id_includes_params_in_response(
@@ -579,26 +575,22 @@ async def test_get_task_by_name_includes_params_in_response(
         assert task_data["params"]["nested"]["numbers"] == [1, 2, 3]
 
     #
-    async def test_list_tasks_handles_null_params_correctly(
+    async def test_list_tasks_omits_params_for_null_params_task(
         self, isolated_client, test_task
     ):
-        """Test that list tasks handles tasks with null params correctly"""
+        """A task created without params also has no `params` key in the list."""
         # When - Request all tasks (test_task has null params)
         response = await isolated_client.get("/tasks")
 
-        # Then - Should succeed and handle null params
+        # Then - The task is present with no params field
         assert response.status_code == 200
         tasks = response.json()
 
-        # Find our test task without params
         null_params_task = next(
             (task for task in tasks if task["id"] == test_task.id), None
         )
         assert null_params_task is not None
-
-        # Verify params field exists and is null
-        assert "params" in null_params_task
-        assert null_params_task["params"] is None
+        assert "params" not in null_params_task
 
     #
     async def test_get_task_by_id_handles_null_params_correctly(