diff --git a/src/cron/isolated-agent/run.ts b/src/cron/isolated-agent/run.ts
index b8dd56d0099..6ec362e3cff 100644
--- a/src/cron/isolated-agent/run.ts
+++ b/src/cron/isolated-agent/run.ts
@@ -15,6 +15,8 @@ import {
   type SourceDeliveryPlan,
   type SourceDeliveryVisibleDelivery,
 } from "../../infra/outbound/source-delivery-plan.js";
+import { logMessageProcessed, logMessageQueued } from "../../logging/diagnostic.js";
+import { stringifyRouteThreadId } from "../../plugin-sdk/channel-route.js";
 import { isCommandLaneTaskTimeoutError } from "../../process/command-queue.js";
 import { CommandLane } from "../../process/lanes.js";
 import { createLazyImportLoader } from "../../shared/lazy-promise.js";
@@ -1184,6 +1186,21 @@ export async function runCronIsolatedAgentTurn(params: {
   // the correct context even if adoptCronRunSessionMetadata() rotates it.
   const initialSessionId = prepared.context.cronSession.sessionEntry.sessionId;
 
+  const turnStartedAtMs = Date.now();
+  const taskLabel =
+    params.job.payload.kind === "agentTurn"
+      ? params.job.name?.trim() || params.job.id
+      : params.job.id;
+  logMessageQueued({
+    sessionId: prepared.context.runSessionId,
+    sessionKey: prepared.context.runSessionKey,
+    channel: "cron",
+    source: "cron-isolated",
+    taskLabel,
+  });
+
+  let outcome: "completed" | "error" = "completed";
+  let outcomeError: string | undefined;
   try {
     const { executeCronRun } = await loadCronExecutorRuntime();
     const execution = await executeCronRun({
@@ -1222,21 +1239,30 @@ export async function runCronIsolatedAgentTurn(params: {
       suppressExecNotifyOnExit: prepared.context.suppressExecNotifyOnExit,
     });
     if (isAborted()) {
+      outcome = "error";
+      outcomeError = abortReason();
       return prepared.context.withRunSession({
         status: "error",
         error: abortReason(),
         diagnostics: createCronRunDiagnosticsFromError("cron-setup", abortReason()),
       });
     }
-    return await finalizeCronRun({
+    const finalized = await finalizeCronRun({
       prepared: prepared.context,
       execution,
       abortReason,
       isAborted,
     });
+    if (finalized.status === "error") {
+      outcome = "error";
+      outcomeError = finalized.error;
+    }
+    return finalized;
   } catch (err) {
     const isCronLaneTimeout = isAborted() || isCronNestedLaneTaskTimeoutError(err);
     const error = isCronLaneTimeout ? abortReason() : String(err);
+    outcome = "error";
+    outcomeError = error;
     return prepared.context.withRunSession({
       status: "error",
       error,
@@ -1246,6 +1272,14 @@ export async function runCronIsolatedAgentTurn(params: {
       ),
     });
   } finally {
+    logMessageProcessed({
+      channel: "cron",
+      sessionId: prepared.context.runSessionId,
+      sessionKey: prepared.context.runSessionKey,
+      durationMs: Date.now() - turnStartedAtMs,
+      outcome,
+      error: outcomeError,
+    });
     // Release runtime references after the run completes (success or failure).
     // The session entry has already been persisted to disk by this point,
     // so the in-memory store and run context can be safely dropped.