diff --git a/packages/cloud-agents/src/server/__tests__/resolveStandardTaskSurface.test.ts b/packages/cloud-agents/src/server/__tests__/resolveStandardTaskSurface.test.ts
index 4e8086e46..aaeee5a96 100644
--- a/packages/cloud-agents/src/server/__tests__/resolveStandardTaskSurface.test.ts
+++ b/packages/cloud-agents/src/server/__tests__/resolveStandardTaskSurface.test.ts
@@ -1,4 +1,8 @@
-import { resolveStandardTaskSurface } from '../cloud-agent-workflow';
+import {
+  isResultOnlyAutomationChatDelivery,
+  resolveStandardTaskSurface,
+  shouldAttachChatLifecycleInstructions,
+} from '../cloud-agent-workflow';
 
 describe('resolveStandardTaskSurface', () => {
   it('prefers Slack channel payload bindings', () => {
@@ -59,3 +63,52 @@ describe('resolveStandardTaskSurface', () => {
     ).toBe('web');
   });
 });
+
+describe('isResultOnlyAutomationChatDelivery', () => {
+  it('uses result-only delivery for an initial automation report', () => {
+    expect(
+      isResultOnlyAutomationChatDelivery({ initiatorKind: 'automation' }),
+    ).toBe(true);
+  });
+
+  it('keeps directed automation follow-ups conversational', () => {
+    expect(
+      isResultOnlyAutomationChatDelivery({
+        initiatorKind: 'automation',
+        slackThreadTs: '123.456',
+      }),
+    ).toBe(false);
+    expect(
+      isResultOnlyAutomationChatDelivery({
+        initiatorKind: 'automation',
+        communicationMessageId: 'message-123',
+      }),
+    ).toBe(false);
+  });
+
+  it('does not change user-initiated chat delivery', () => {
+    expect(isResultOnlyAutomationChatDelivery({ initiatorKind: 'user' })).toBe(
+      false,
+    );
+  });
+});
+
+describe('shouldAttachChatLifecycleInstructions', () => {
+  it('omits generic lifecycle instructions from initial automation reports', () => {
+    expect(
+      shouldAttachChatLifecycleInstructions({
+        inheritedCommunicationContext: false,
+        resultOnlyChatDelivery: true,
+      }),
+    ).toBe(false);
+  });
+
+  it('keeps lifecycle instructions for directed follow-ups', () => {
+    expect(
+      shouldAttachChatLifecycleInstructions({
+        inheritedCommunicationContext: false,
+        resultOnlyChatDelivery: false,
+      }),
+    ).toBe(true);
+  });
+});
diff --git a/packages/cloud-agents/src/server/cloud-agent-workflow.ts b/packages/cloud-agents/src/server/cloud-agent-workflow.ts
index 8a9c9f219..be5e46570 100644
--- a/packages/cloud-agents/src/server/cloud-agent-workflow.ts
+++ b/packages/cloud-agents/src/server/cloud-agent-workflow.ts
@@ -105,6 +105,30 @@ export function resolveStandardTaskSurface({
   }
 }
 
+export function isResultOnlyAutomationChatDelivery({
+  initiatorKind,
+  slackThreadTs,
+  communicationMessageId,
+}: {
+  initiatorKind?: string | null;
+  slackThreadTs?: string | null;
+  communicationMessageId?: string | null;
+}): boolean {
+  return (
+    initiatorKind === 'automation' && !slackThreadTs && !communicationMessageId
+  );
+}
+
+export function shouldAttachChatLifecycleInstructions({
+  inheritedCommunicationContext,
+  resultOnlyChatDelivery,
+}: {
+  inheritedCommunicationContext: boolean;
+  resultOnlyChatDelivery: boolean;
+}): boolean {
+  return !inheritedCommunicationContext && !resultOnlyChatDelivery;
+}
+
 export async function generatePrompt({
   taskRun,
   taskSpec,
@@ -147,6 +171,7 @@ export async function generatePrompt({
       actorDisplayName: true,
       slackThreadTs: true,
       surface: true,
+      initiatorKind: true,
     },
   });
   const commitAuthor = taskRow
@@ -316,6 +341,16 @@ export async function generatePrompt({
       const communicationMessageId = getCommunicationMessageIdFromTaskPayload(
         taskSpec.payload,
       );
+      const resultOnlyChatDelivery = isResultOnlyAutomationChatDelivery({
+        initiatorKind: taskRow?.initiatorKind,
+        slackThreadTs,
+        communicationMessageId,
+      });
+      const attachChatLifecycleInstructions =
+        shouldAttachChatLifecycleInstructions({
+          inheritedCommunicationContext,
+          resultOnlyChatDelivery,
+        });
       const teamsTenantId = getCommunicationTenantIdFromTaskPayload(
         taskSpec.payload,
       );
@@ -386,6 +421,7 @@ export async function generatePrompt({
         sourceChannelId: communicationChannelId ?? undefined,
         sourceThreadId: communicationThreadId ?? undefined,
         sourceMessageId: communicationMessageId ?? undefined,
+        resultOnlyChatDelivery,
         interactiveMode: taskSpec.payload.bootstrap?.interactiveMode,
         requestFormat,
         linkedWorkItems: taskSpec.payload.linkedWorkItems,
@@ -398,7 +434,7 @@ export async function generatePrompt({
         prAction,
       });
 
-      if (!inheritedCommunicationContext && slackChannel && slackThreadTs) {
+      if (attachChatLifecycleInstructions && slackChannel && slackThreadTs) {
         const slackInstructions = buildSlackMessageInstructions({
           includeRequestUserInputGuidance: true,
         });
@@ -407,7 +443,7 @@ export async function generatePrompt({
           : slackInstructions;
       }
 
-      if (!inheritedCommunicationContext && nonSlackChatProvider) {
+      if (attachChatLifecycleInstructions && nonSlackChatProvider) {
         const chatInstructions =
           nonSlackChatProvider === 'teams'
             ? buildTeamsMessageInstructions()
diff --git a/packages/cloud-agents/src/server/workflows/__tests__/standardTaskSurfaceContext.test.ts b/packages/cloud-agents/src/server/workflows/__tests__/standardTaskSurfaceContext.test.ts
index 0f4b4192c..1b787c5e1 100644
--- a/packages/cloud-agents/src/server/workflows/__tests__/standardTaskSurfaceContext.test.ts
+++ b/packages/cloud-agents/src/server/workflows/__tests__/standardTaskSurfaceContext.test.ts
@@ -68,6 +68,31 @@ describe('Standard Task surface context', () => {
     );
   });
 
+  it('keeps initial automation chat delivery silent until the result', () => {
+    const { harnessInstructions } = standardTask({
+      description: 'Scan repositories and report suggestions',
+      repo: 'Roomote/example-app',
+      taskSurface: 'slack',
+      resultOnlyChatDelivery: true,
+    });
+
+    expect(harnessInstructions).toContain(
+      'This run was launched by an automation with slack as its report destination. It was not launched by a directed chat turn.',
+    );
+    expect(harnessInstructions).toContain(
+      "The automation's chat message must always be its result, never an in-progress message.",
+    );
+    expect(harnessInstructions).toContain(
+      'The automation-specific prompt remains authoritative for whether to report, which chat tools to use, and the number and shape of final messages.',
+    );
+    expect(harnessInstructions).not.toContain(
+      'The first and only chat-visible reply for this automation turn must use `send_chat_reply`',
+    );
+    expect(harnessInstructions).not.toContain(
+      'This run was launched from a Slack conversation surface',
+    );
+  });
+
   it('labels Gitea-started review tasks as Gitea pull request runs', () => {
     const { harnessInstructions } = standardTask({
       description: 'Review pull request',
diff --git a/packages/cloud-agents/src/server/workflows/standardTask.ts b/packages/cloud-agents/src/server/workflows/standardTask.ts
index d04066b3f..213d26049 100644
--- a/packages/cloud-agents/src/server/workflows/standardTask.ts
+++ b/packages/cloud-agents/src/server/workflows/standardTask.ts
@@ -73,6 +73,7 @@ export function standardTask({
   sourceChannelId,
   sourceThreadId,
   sourceMessageId,
+  resultOnlyChatDelivery = false,
   linkedWorkItems,
   interactiveMode = false,
   requestFormat = 'plain',
@@ -122,6 +123,8 @@ export function standardTask({
   sourceChannelId?: string;
   sourceThreadId?: string;
   sourceMessageId?: string;
+  /** Initial automation report with no directed chat turn to acknowledge. */
+  resultOnlyChatDelivery?: boolean;
   linkedWorkItems?: LinkedWorkItem[];
   interactiveMode?: boolean;
   requestFormat?: 'plain' | 'structured';
@@ -258,6 +261,11 @@ export function standardTask({
 `
     : '';
   const defaultMode = interactiveMode ? 'interactive' : 'autonomous';
+  const isChatTaskSurface =
+    taskSurface === 'slack' ||
+    taskSurface === 'teams' ||
+    taskSurface === 'telegram' ||
+    taskSurface === 'discord';
   const taskSurfaceContext =
     taskSurface === 'slack'
       ? `
@@ -330,6 +338,15 @@ ${buildGitHubMessageInstructions()}`
     <rule>If a workflow or packaged skill distinguishes web dashboard tasks from other surfaces, treat this run as a web dashboard task.</rule>
     <rule>When a secure web-task flow exists for the current step, prefer that flow over asking the user to paste secrets into chat or make local-only task edits.</rule>
   </task_surface_context>`;
+  const effectiveTaskSurfaceContext =
+    resultOnlyChatDelivery && isChatTaskSurface
+      ? `
+  <task_surface_context>
+    <rule>This run was launched by an automation with ${taskSurface} as its report destination. It was not launched by a directed chat turn.</rule>
+    <rule>The automation's chat message must always be its result, never an in-progress message. Keep acknowledgements, reactions, progress updates, partial findings, and routine status in the web task only.</rule>
+    <rule>The automation-specific prompt remains authoritative for whether to report, which chat tools to use, and the number and shape of final messages. This context only suppresses acknowledgements and in-progress updates before that delivery contract's result.</rule>
+  </task_surface_context>`
+      : taskSurfaceContext;
   const sourceContext =
     sourceProvider && (sourceChannelId || sourceThreadId || sourceMessageId)
       ? `
@@ -404,7 +421,7 @@ ${buildGitHubMessageInstructions()}`
     <visual_proof_context>Screencast auto-classification is disabled for this task.</visual_proof_context>
   </task_context>
 
-  ${taskSurfaceContext}
+  ${effectiveTaskSurfaceContext}
   ${sourceContext}
   ${sourceControlContext}
   ${codeReviewSelfReviewCloseoutContext}