diff --git a/CHANGELOG.md b/CHANGELOG.md
index d4110aa124c..ead00c6eaeb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -244,6 +244,7 @@ Docs: https://docs.openclaw.ai
 - Agents/failover: scope assistant-side fallback classification and surfaced provider errors to the current attempt instead of stale session history, so cross-provider fallback runs stop inheriting the previous provider's failure. (#62907) Thanks @stainlu.
 - MiniMax/OAuth: write `api: "anthropic-messages"` and `authHeader: true` into the `minimax-portal` config patch during `openclaw configure`, so re-authenticated portal setups keep Bearer auth routing working. (#64964) Thanks @ryanlee666.
 - Agents/tools: stop repeated unavailable-tool retries from escaping loop detection when the model changes arguments, and rewrite over-threshold unknown tool calls into plain assistant text before dispatch. (#65922) Thanks @dutifulbob.
+- Cron/announce delivery: tell isolated cron jobs to return the full response exactly instead of a summary, so structured `--announce` deliveries stop dropping fields nondeterministically. (#65638) Thanks @srinivaspavan9 and @vincentkoc.
 
 ## 2026.4.10
 
diff --git a/src/cron/isolated-agent/run.message-tool-policy.test.ts b/src/cron/isolated-agent/run.message-tool-policy.test.ts
index 73cc2dc4db8..3bff3561411 100644
--- a/src/cron/isolated-agent/run.message-tool-policy.test.ts
+++ b/src/cron/isolated-agent/run.message-tool-policy.test.ts
@@ -165,3 +165,71 @@ describe("runCronIsolatedAgentTurn message tool policy", () => {
     );
   });
 });
+
+describe("runCronIsolatedAgentTurn delivery instruction", () => {
+  let previousFastTestEnv: string | undefined;
+
+  beforeEach(() => {
+    previousFastTestEnv = clearFastTestEnv();
+    resetRunCronIsolatedAgentTurnHarness();
+    resolveDeliveryTargetMock.mockResolvedValue({
+      ok: true,
+      channel: "telegram",
+      to: "123",
+      accountId: undefined,
+      error: undefined,
+    });
+  });
+
+  afterEach(() => {
+    restoreFastTestEnv(previousFastTestEnv);
+  });
+
+  it("appends a plain-text delivery instruction to the prompt when delivery is requested", async () => {
+    mockRunCronFallbackPassthrough();
+    resolveCronDeliveryPlanMock.mockReturnValue({
+      requested: true,
+      mode: "announce",
+      channel: "telegram",
+      to: "123",
+    });
+
+    await runCronIsolatedAgentTurn(makeParams());
+
+    expect(runEmbeddedPiAgentMock).toHaveBeenCalledTimes(1);
+    const prompt: string = runEmbeddedPiAgentMock.mock.calls[0]?.[0]?.prompt ?? "";
+    expect(prompt).toContain("Return your response as plain text");
+    expect(prompt).toContain("it will be delivered automatically");
+  });
+
+  it("does not append a delivery instruction when delivery is not requested", async () => {
+    mockRunCronFallbackPassthrough();
+    resolveCronDeliveryPlanMock.mockReturnValue({ requested: false, mode: "none" });
+
+    await runCronIsolatedAgentTurn(makeParams());
+
+    expect(runEmbeddedPiAgentMock).toHaveBeenCalledTimes(1);
+    const prompt: string = runEmbeddedPiAgentMock.mock.calls[0]?.[0]?.prompt ?? "";
+    expect(prompt).not.toContain("Return your response as plain text");
+    expect(prompt).not.toContain("it will be delivered automatically");
+  });
+
+  it("does not instruct the agent to summarize when delivery is requested", async () => {
+    // Regression for https://github.com/openclaw/openclaw/issues/58535:
+    // "summary" caused LLMs to condense structured output and drop fields
+    // non-deterministically on every run.
+    mockRunCronFallbackPassthrough();
+    resolveCronDeliveryPlanMock.mockReturnValue({
+      requested: true,
+      mode: "announce",
+      channel: "telegram",
+      to: "123",
+    });
+
+    await runCronIsolatedAgentTurn(makeParams());
+
+    expect(runEmbeddedPiAgentMock).toHaveBeenCalledTimes(1);
+    const prompt: string = runEmbeddedPiAgentMock.mock.calls[0]?.[0]?.prompt ?? "";
+    expect(prompt).not.toMatch(/\bsummary\b/i);
+  });
+});
diff --git a/src/cron/isolated-agent/run.ts b/src/cron/isolated-agent/run.ts
index 4e7af581dde..6b25464c3c8 100644
--- a/src/cron/isolated-agent/run.ts
+++ b/src/cron/isolated-agent/run.ts
@@ -193,7 +193,7 @@ function appendCronDeliveryInstruction(params: {
   if (!params.deliveryRequested) {
     return params.commandBody;
   }
-  return `${params.commandBody}\n\nReturn your summary as plain text; it will be delivered automatically. If the task explicitly calls for messaging a specific external recipient, note who/where it should go instead of sending it yourself.`.trim();
+  return `${params.commandBody}\n\nReturn your response as plain text; it will be delivered automatically. If the task explicitly calls for messaging a specific external recipient, note who/where it should go instead of sending it yourself.`.trim();
 }
 
 function resolvePositiveContextTokens(value: unknown): number | undefined {