diff --git a/agent-side-effect-tools.mjs b/agent-side-effect-tools.mjs
index 7c5e257..fd137a8 100644
--- a/agent-side-effect-tools.mjs
+++ b/agent-side-effect-tools.mjs
@@ -33,6 +33,20 @@ export async function executeScheduledTaskCreateTool(args, {
   return workerWarning ? { ...task, workerWarning } : task;
 }
 
+export async function executeScheduledTaskUpdateSpecTool(args, {
+  userId,
+  scheduledTaskService,
+} = {}) {
+  if (!scheduledTaskService) throw new Error('scheduledTaskService 不可用');
+  return scheduledTaskService.updateTaskSpec({
+    userId,
+    taskId: args.taskId,
+    taskSpec: args.taskSpec ?? null,
+    title: args.title ?? null,
+    mergeTaskSpec: Boolean(args.mergeTaskSpec),
+  });
+}
+
 export async function executeScheduleCreateItemTool(args, {
   userId,
   scheduleService,
@@ -134,6 +148,10 @@ export async function commitAgentSideEffectTool(toolName, toolArgs, services) {
     const task = await executeScheduledTaskCreateTool(toolArgs, services);
     return { kind: 'scheduled_task', task };
   }
+  if (name === 'scheduled_task_update_spec') {
+    const task = await executeScheduledTaskUpdateSpecTool(toolArgs, services);
+    return { kind: 'scheduled_task', task, updated: true };
+  }
   if (name === 'schedule_create_item') {
     const result = await executeScheduleCreateItemTool(toolArgs, services);
     return { kind: 'schedule_item', ...result };
diff --git a/agent-side-effect-tools.test.mjs b/agent-side-effect-tools.test.mjs
new file mode 100644
index 0000000..bf03d3f
--- /dev/null
+++ b/agent-side-effect-tools.test.mjs
@@ -0,0 +1,43 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import {
+  commitAgentSideEffectTool,
+  executeScheduledTaskUpdateSpecTool,
+} from './agent-side-effect-tools.mjs';
+
+test('executeScheduledTaskUpdateSpecTool delegates to scheduledTaskService.updateTaskSpec', async () => {
+  const calls = [];
+  const task = await executeScheduledTaskUpdateSpecTool({
+    taskId: 'task-1',
+    taskSpec: '新规范',
+    mergeTaskSpec: true,
+  }, {
+    userId: 'user-1',
+    scheduledTaskService: {
+      async updateTaskSpec(payload) {
+        calls.push(payload);
+        return { id: 'task-1', taskSpec: 'merged spec', title: '新闻' };
+      },
+    },
+  });
+  assert.equal(calls[0].taskId, 'task-1');
+  assert.equal(calls[0].mergeTaskSpec, true);
+  assert.equal(task.title, '新闻');
+});
+
+test('commitAgentSideEffectTool supports scheduled_task_update_spec', async () => {
+  const committed = await commitAgentSideEffectTool('scheduled_task_update_spec', {
+    taskId: 'task-1',
+    taskSpec: '标准格式说明',
+    mergeTaskSpec: true,
+  }, {
+    userId: 'user-1',
+    scheduledTaskService: {
+      async updateTaskSpec() {
+        return { id: 'task-1', taskSpec: '标准格式说明', status: 'active' };
+      },
+    },
+  });
+  assert.equal(committed.kind, 'scheduled_task');
+  assert.equal(committed.updated, true);
+});
diff --git a/capabilities.mjs b/capabilities.mjs
index 115a8aa..1f33fc2 100644
--- a/capabilities.mjs
+++ b/capabilities.mjs
@@ -469,6 +469,7 @@ export function sandboxMcpTools(capabilities) {
       'scheduled_task_create',
       'scheduled_task_list',
       'scheduled_task_cancel',
+      'scheduled_task_update_spec',
     );
   }
   return tools;
diff --git a/capabilities.test.mjs b/capabilities.test.mjs
index c8a4584..a0faab1 100644
--- a/capabilities.test.mjs
+++ b/capabilities.test.mjs
@@ -398,6 +398,7 @@ test('sandboxMcpTools returns correct tool list based on capabilities', () => {
     'scheduled_task_create',
     'scheduled_task_list',
     'scheduled_task_cancel',
+    'scheduled_task_update_spec',
   ]);
 
   const withBrowse = { ...base, code_browse: true };
@@ -424,6 +425,7 @@ test('private_data_space alone exposes private data tools through sandbox MCP',
     'scheduled_task_create',
     'scheduled_task_list',
     'scheduled_task_cancel',
+    'scheduled_task_update_spec',
   ]);
 
   const policy = buildAgentExtensionPolicy(caps, {
@@ -458,6 +460,7 @@ test('private_data_space alone exposes private data tools through sandbox MCP',
     'scheduled_task_create',
     'scheduled_task_list',
     'scheduled_task_cancel',
+    'scheduled_task_update_spec',
   ]);
 });
 
diff --git a/mindspace-sandbox-mcp.mjs b/mindspace-sandbox-mcp.mjs
index 583f5bf..6ba6550 100644
--- a/mindspace-sandbox-mcp.mjs
+++ b/mindspace-sandbox-mcp.mjs
@@ -21,6 +21,7 @@ import {
   executeScheduleCreateItemTool,
   executeScheduleCreateReminderTool,
   executeScheduledTaskCreateTool,
+  executeScheduledTaskUpdateSpecTool,
 } from './agent-side-effect-tools.mjs';
 import { createIntentDraftService } from './intent-draft-service.mjs';
 import { requireUserConfirmForSideEffectTool } from './intent-tool-confirm-gate.mjs';
@@ -681,15 +682,42 @@ if (isScheduleConfigured()) {
     },
     {
       name: 'scheduled_task_cancel',
-      description: '取消当前用户的一个定时自动任务。需提供 taskId 或 titleMatch。',
+      description:
+        '取消当前用户的一个定时自动任务。优先传 taskId（先调用 scheduled_task_list 拿到 id 后再取消）。'
+        + '只有在列表里已明确对应条目、且 taskId 已知时才能取消；不要猜测 titleMatch。',
       inputSchema: {
         type: 'object',
         properties: {
-          taskId: { type: 'string', description: '任务 ID，优先使用' },
-          titleMatch: { type: 'string', description: '按标题模糊匹配最近一条 active 任务' },
+          taskId: { type: 'string', description: '任务 ID（来自 scheduled_task_list，优先使用）' },
+          titleMatch: {
+            type: 'string',
+            description: 'Deprecated fallback：仅当 taskId 不可用且标题关键词来自 list 结果时使用',
+          },
         },
       },
     },
+    {
+      name: 'scheduled_task_update_spec',
+      description:
+        '更新已有定时自动任务的 taskSpec（执行说明）或标题。'
+        + '用于用户补充格式标准、参考页面、长期执行约束等；先 scheduled_task_list 拿 taskId。',
+      inputSchema: {
+        type: 'object',
+        properties: {
+          taskId: { type: 'string', description: '任务 ID（来自 scheduled_task_list，必填）' },
+          taskSpec: {
+            type: 'string',
+            description: '新的完整执行说明；与 mergeTaskSpec 二选一',
+          },
+          title: { type: 'string', description: '可选：更新任务标题' },
+          mergeTaskSpec: {
+            type: 'boolean',
+            description: '为 true 时将 taskSpec 追加到现有说明末尾（适合补充格式/规范）',
+          },
+        },
+        required: ['taskId'],
+      },
+    },
   );
 }
 
@@ -1234,6 +1262,13 @@ async function callTool(name, args) {
       });
       return [{ type: 'text', text: JSON.stringify(task, null, 2) }];
     }
+    case 'scheduled_task_update_spec': {
+      const task = await executeScheduledTaskUpdateSpecTool(args, {
+        userId: PRIVATE_DATA_USER_ID,
+        scheduledTaskService: getScheduledTaskService(),
+      });
+      return [{ type: 'text', text: JSON.stringify(task, null, 2) }];
+    }
     default:
       throw new Error(`未知工具：${name}`);
   }
diff --git a/scheduled-task-service.mjs b/scheduled-task-service.mjs
index 25a741d..52b14d7 100644
--- a/scheduled-task-service.mjs
+++ b/scheduled-task-service.mjs
@@ -218,6 +218,51 @@ export function createScheduledTaskService(pool, { defaultTimezone = DEFAULT_TIM
     return rows.map(rowToTask);
   };
 
+  const updateTaskSpec = async ({
+    userId,
+    taskId,
+    taskSpec = null,
+    title = null,
+    mergeTaskSpec = false,
+  } = {}) => {
+    if (!userId) throw new Error('缺少用户');
+    const safeTaskId = String(taskId ?? '').trim();
+    if (!safeTaskId) throw new Error('缺少 taskId');
+    const safeTaskSpec = taskSpec == null ? null : String(taskSpec).trim();
+    const safeTitle = title == null ? null : String(title).trim();
+    if (!safeTaskSpec && !safeTitle) throw new Error('缺少 taskSpec 或 title');
+
+    const [rows] = await pool.query(
+      `SELECT *
+       FROM h5_scheduled_tasks
+       WHERE id = ? AND user_id = ? AND status IN ('active', 'locked', 'failed')
+       LIMIT 1`,
+      [safeTaskId, userId],
+    );
+    const existing = rows[0];
+    if (!existing) throw new Error('未找到可更新的定时任务');
+
+    let nextSpec = existing.task_spec;
+    if (safeTaskSpec) {
+      nextSpec = mergeTaskSpec
+        ? [String(existing.task_spec ?? '').trim(), safeTaskSpec].filter(Boolean).join('\n\n')
+        : safeTaskSpec;
+    }
+    const nextTitle = safeTitle || existing.title;
+    const ts = clock.now();
+    await pool.query(
+      `UPDATE h5_scheduled_tasks
+       SET task_spec = ?, title = ?, updated_at = ?
+       WHERE id = ?`,
+      [nextSpec, nextTitle, ts, safeTaskId],
+    );
+    const [updated] = await pool.query(
+      `SELECT * FROM h5_scheduled_tasks WHERE id = ? LIMIT 1`,
+      [safeTaskId],
+    );
+    return rowToTask(updated[0]);
+  };
+
   const cancelTask = async ({
     userId,
     taskId = null,
@@ -385,6 +430,7 @@ export function createScheduledTaskService(pool, { defaultTimezone = DEFAULT_TIM
   return {
     createTask,
     listTasks,
+    updateTaskSpec,
     cancelTask,
     listDueTasks,
     lockTask,
diff --git a/scheduled-task-service.test.mjs b/scheduled-task-service.test.mjs
index ddb04d9..1efd95e 100644
--- a/scheduled-task-service.test.mjs
+++ b/scheduled-task-service.test.mjs
@@ -275,3 +275,67 @@ test('markTaskSucceeded schedules next run for daily task', async () => {
   assert.ok(result.nextRunAt > Date.parse('2026-07-31T02:00:00+08:00'));
   assert.equal(updates.length, 1);
 });
+
+test('updateTaskSpec replaces or merges taskSpec', async () => {
+  const activeTask = {
+    id: 'task-news',
+    user_id: 'user-1',
+    title: '每日新闻早报页面（5:30）',
+    task_spec: '按旧格式生成新闻页',
+    recurrence: 'daily',
+    hour: 5,
+    minute: 30,
+    weekday: null,
+    timezone: 'Asia/Shanghai',
+    next_run_at: 1780000000000,
+    last_run_at: null,
+    notify_channel: 'both',
+    status: 'active',
+    attempts: 0,
+    last_error: null,
+    last_result_json: null,
+    source_channel: 'agent',
+    source_session_id: null,
+    source_message_id: null,
+    source_text: null,
+    created_at: 1780000000000,
+    updated_at: 1780000000000,
+  };
+  let stored = { ...activeTask };
+  const service = createScheduledTaskService({
+    async query(sql, params) {
+      if (sql.includes('FROM h5_scheduled_tasks') && sql.includes('status IN')) {
+        return [[stored]];
+      }
+      if (sql.includes('UPDATE h5_scheduled_tasks') && sql.includes('task_spec')) {
+        stored = {
+          ...stored,
+          task_spec: params[0],
+          title: params[1],
+          updated_at: params[2],
+        };
+        return [{ affectedRows: 1 }];
+      }
+      if (sql.includes('SELECT * FROM h5_scheduled_tasks WHERE id = ? LIMIT 1')) {
+        return [[stored]];
+      }
+      return [[]];
+    },
+  });
+
+  const merged = await service.updateTaskSpec({
+    userId: 'user-1',
+    taskId: 'task-news',
+    taskSpec: '参照 daily-news-0829.html 作为标准格式',
+    mergeTaskSpec: true,
+  });
+  assert.match(merged.taskSpec, /旧格式/u);
+  assert.match(merged.taskSpec, /daily-news-0829/u);
+
+  const replaced = await service.updateTaskSpec({
+    userId: 'user-1',
+    taskId: 'task-news',
+    taskSpec: '全新执行说明',
+  });
+  assert.equal(replaced.taskSpec, '全新执行说明');
+});
diff --git a/skills/scheduled-task-automation/SKILL.md b/skills/scheduled-task-automation/SKILL.md
index d11086b..9edeedb 100644
--- a/skills/scheduled-task-automation/SKILL.md
+++ b/skills/scheduled-task-automation/SKILL.md
@@ -10,21 +10,23 @@ description: 处理定时自动任务（Scheduled Automation）：澄清执行
 ## 适用范围
 
 - 创建一次性或循环的定时自动任务（Scheduled Task / Recurring Automation）
-- 查询、取消当前用户的定时任务
+- 查询、取消、**更新执行说明（taskSpec）** 当前用户的定时任务
 - 澄清缺失的执行时间或任务内容
 
 ## 边界
 
 1. **不**处理纯提醒、待办记录、日程查询 —— 那些交给 `schedule-assistant`。
-2. **不**在当前对话里立即执行长任务；本 skill 只负责**写入定时订阅**。
+2. **不**在当前对话里立即执行长任务；本 skill 只负责**写入/更新定时订阅**。
 3. 只能操作当前用户的数据；工具成功返回前，不能说「已经设置好了」。
 4. 信息不完整时先追问，禁止臆造时间或任务内容。
+5. 用户是在**补充已有任务的长期规范/格式/参考页**（如「以后新闻按 8/29 格式」）时，用 `scheduled_task_update_spec`，**不要**去生成 HTML 页面。
 
 ## 可用工具
 
-- `scheduled_task_create`
+- `scheduled_task_create`（创建，需用户确认卡片）
 - `scheduled_task_list`
 - `scheduled_task_cancel`
+- `scheduled_task_update_spec`（更新 taskSpec / 标题，直接写入）
 
 ## 必填信息（创建前必须齐全）
 
@@ -43,15 +45,12 @@ description: 处理定时自动任务（Scheduled Automation）：澄清执行
 
 ## 工作规则
 
-1. 先判断用户是要**创建**、**查询**还是**取消**定时自动任务。
+1. 先判断用户是要**创建**、**查询**、**取消**还是**更新规范**。
 2. 缺时间或缺任务内容时，一次只追问最小必要信息。
-3. 创建成功后，用用户能理解的话说明：
-   - 何时执行
-   - 执行什么
-   - 是一次性还是循环
-   - 结果会通过哪个通道推送（默认微信 + 站内）
-4. 取消时优先用 `taskId`；用户只说任务名时可传 `titleMatch`。
-5. 若提示里给出了 `sourceMessageId`，调用 `scheduled_task_create` 时必须原样传入。
+3. **取消 / 更新**前必须先 `scheduled_task_list`，用返回的 `taskId` 操作；由你理解用户指哪一条，不要猜 titleMatch。
+4. **更新规范**：用户补充格式标准、参考页面 URL、排版约束时，对目标任务调用 `scheduled_task_update_spec`，`mergeTaskSpec: true` 追加说明。
+5. 创建成功后，用用户能理解的话说明何时执行、执行什么、recurrence、推送通道。
+6. 若提示里给出了 `sourceMessageId`，调用 `scheduled_task_create` 时必须原样传入。
 
 ## 回复要求
 
@@ -65,3 +64,8 @@ description: 处理定时自动任务（Scheduled Automation）：澄清执行
 
 助手：（信息齐全后调用 `scheduled_task_create`）
 已设置循环任务：每天 06:00（北京时间）自动搜索并生成「今日新闻页」，完成后推送链接。
+
+用户：以后新闻早报都按 8 月 29 号那版格式执行
+
+助手：（`scheduled_task_list` → 对 5:30 新闻任务 `scheduled_task_update_spec` + mergeTaskSpec）
+已更新定时任务的执行说明，之后到点会按新格式生成。
diff --git a/wechat/handlers/scheduled-task.mjs b/wechat/handlers/scheduled-task.mjs
index 2cab61c..6ee605a 100644
--- a/wechat/handlers/scheduled-task.mjs
+++ b/wechat/handlers/scheduled-task.mjs
@@ -4,8 +4,6 @@ import {
   parseScheduledTaskIntent,
 } from '../../scheduled-task-intent.mjs';
 
-const WEEKDAY_NAMES = ['周日', '周一', '周二', '周三', '周四', '周五', '周六'];
-
 export async function handleWechatScheduledTaskIntent({
   intent,
   user,
@@ -31,21 +29,10 @@ export async function handleWechatScheduledTaskIntent({
       return formatScheduledTaskListReply(tasks);
     }
 
-    if (taskIntent.action === 'cancel_scheduled_task') {
-      const titleMatch = String(intent.agentText ?? '')
-        .replace(/(?:取消|停止|关闭|删除|我的|定时|自动|任务)/gu, ' ')
-        .trim();
-      if (!titleMatch) {
-        return '请告诉我要取消哪一条定时任务，或提供任务名称关键词。';
-      }
-      const task = await scheduledTaskService.cancelTask({
-        userId: user.userId,
-        titleMatch,
-      });
-      return `已取消定时任务：${task.title}`;
-    }
-
-    if (taskIntent.action === 'create_scheduled_task') {
+    if (
+      taskIntent.action === 'create_scheduled_task'
+      || taskIntent.action === 'cancel_scheduled_task'
+    ) {
       return null;
     }
   } catch (err) {
diff --git a/wechat/handlers/scheduled-task.test.mjs b/wechat/handlers/scheduled-task.test.mjs
index 548486c..1b70a1c 100644
--- a/wechat/handlers/scheduled-task.test.mjs
+++ b/wechat/handlers/scheduled-task.test.mjs
@@ -36,6 +36,23 @@ test('handleWechatScheduledTaskIntent passes incomplete create requests to goose
   assert.equal(reply, null);
 });
 
+test('handleWechatScheduledTaskIntent passes cancel requests to goose', async () => {
+  const reply = await handleWechatScheduledTaskIntent({
+    intent: {
+      msgType: 'text',
+      agentText: '取消定时推送苏州天气任务',
+      msgId: 'msg-123-1',
+    },
+    user: { userId: 'user-123' },
+    scheduledTaskService: {
+      async cancelTask() {
+        throw new Error('should not cancel from inbound regex');
+      },
+    },
+  });
+  assert.equal(reply, null);
+});
+
 test('handleWechatScheduledTaskIntent ignores non automation text', async () => {
   const reply = await handleWechatScheduledTaskIntent({
     intent: {
diff --git a/wechat/prompts/chat-general.mjs b/wechat/prompts/chat-general.mjs
index e518e86..84329e6 100644
--- a/wechat/prompts/chat-general.mjs
+++ b/wechat/prompts/chat-general.mjs
@@ -4,7 +4,11 @@ import {
   isPageDataIntent,
 } from '../../chat-skills.mjs';
 import { shouldUseScheduleAssistant } from '../../schedule-intent.mjs';
-import { shouldUseScheduledTaskAutomation } from '../../scheduled-task-intent.mjs';
+import {
+  isScheduledTaskIntent,
+  parseScheduledTaskIntent,
+  shouldUseScheduledTaskAutomation,
+} from '../../scheduled-task-intent.mjs';
 import { buildCurrentTimeAgentPrefix } from '../../user-memory-profile.mjs';
 import { isPageGenerateText, wantsDocxDownload } from '../intent/patterns.mjs';
 import { buildWechatStandaloneImageInstruction } from '../image-generation-policy.mjs';
@@ -82,12 +86,18 @@ export function buildWechatAgentPrompt(intent, {
         '',
       ].filter(Boolean).join('\n')
     : '';
-  const scheduledTaskAutomationHint = shouldUseScheduledTaskAutomation(agentText)
+  const scheduledTaskIntent = parseScheduledTaskIntent(agentText);
+  const scheduledTaskAutomationHint = (
+    shouldUseScheduledTaskAutomation(agentText)
+    || isScheduledTaskIntent(scheduledTaskIntent)
+  )
     ? [
-        '【定时自动任务要求】这条消息是 Scheduled Automation（到点自动执行并推送结果），不是待办提醒。',
+        '【定时自动任务要求】这条消息涉及 Scheduled Automation（到点自动执行并推送结果），不是待办提醒。',
         '开始前先加载 `scheduled-task-automation` skill，并严格按 skill 边界执行。',
-        '先澄清缺失的执行时间或 taskSpec，再调用 scheduled_task_create / scheduled_task_list / scheduled_task_cancel。',
-        '禁止在当前对话立即执行长任务；工具成功返回后才能确认已设置。',
+        '创建：澄清缺失的执行时间或 taskSpec，再调用 scheduled_task_create（需用户确认卡片）。',
+        '取消/更新规范：必须先 scheduled_task_list 拿 taskId；取消用 scheduled_task_cancel，补充格式/长期约束用 scheduled_task_update_spec（可 mergeTaskSpec）。',
+        '若用户只是在补充已有定时任务的执行规范（不是要做新页面），禁止走 static-page-publish 页面交付链路。',
+        '禁止在当前对话立即执行长任务；工具成功返回后才能确认已设置/已取消。',
         '一次性任务用 runAtLocal；循环任务用 hour/minute/weekday，禁止自行估算 Unix 毫秒。',
         intent?.msgId ? `调用 scheduled_task_create 时必须传入 sourceMessageId: ${intent.msgId}` : '',
         '',
diff --git a/wechat/prompts/page-generate.mjs b/wechat/prompts/page-generate.mjs
index b84bb0c..12021ad 100644
--- a/wechat/prompts/page-generate.mjs
+++ b/wechat/prompts/page-generate.mjs
@@ -66,6 +66,7 @@ export function buildPageGenerateAgentPrompt(
   return [
     '【微信服务号 · 页面生成任务】',
     '这是服务号专用页面生成，不是普通聊天。必须按步骤完成，未完成前禁止告诉用户“已生成/已发布”。',
+    '【定时任务规范】若用户是在为已有定时自动任务补充长期格式/参考页/执行约束（不是要你此刻写 HTML），改加载 scheduled-task-automation，用 scheduled_task_list + scheduled_task_update_spec；禁止走本页面交付链路。',
     '',
     docxBlock,
     imageBlock,