diff --git a/examples/showcases/claude-managed-agents/server/src/setup.test.ts b/examples/showcases/claude-managed-agents/server/src/setup.test.ts
index ca796152ab..456c1a67b4 100644
--- a/examples/showcases/claude-managed-agents/server/src/setup.test.ts
+++ b/examples/showcases/claude-managed-agents/server/src/setup.test.ts
@@ -1,8 +1,15 @@
 import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
 import test from "node:test";
 import type { AgentCreateParams } from "@anthropic-ai/sdk/resources/beta/agents/agents";
 
-import { parseAgentIds, provisionAgentResources } from "./setup.ts";
+import {
+  parseAgentIds,
+  provisionAgentResources,
+  readAgentIdsFile,
+} from "./setup.ts";
 
 function createCapturingClient() {
   let agentParams: AgentCreateParams | undefined;
@@ -84,6 +91,18 @@ test("accepts valid persisted agent IDs", () => {
   );
 });
 
+test("rejects malformed persisted agent-ID files", (t) => {
+  const directory = fs.mkdtempSync(path.join(os.tmpdir(), "agent-ids-test-"));
+  t.after(() => fs.rmSync(directory, { recursive: true }));
+  const file = path.join(directory, "agent-ids.json");
+  fs.writeFileSync(file, JSON.stringify({ environmentId: "env_test" }));
+
+  assert.throws(
+    () => readAgentIdsFile(file),
+    /expected non-empty environmentId and agentId strings/,
+  );
+});
+
 test("deletes the environment when agent creation fails", async () => {
   const failure = new Error("agent creation failed");
   const deletedEnvironmentIds: string[] = [];
diff --git a/examples/showcases/claude-managed-agents/server/src/setup.ts b/examples/showcases/claude-managed-agents/server/src/setup.ts
index 51133c6f58..98a7f42ea6 100644
--- a/examples/showcases/claude-managed-agents/server/src/setup.ts
+++ b/examples/showcases/claude-managed-agents/server/src/setup.ts
@@ -47,6 +47,10 @@ export function parseAgentIds(value: unknown): AgentIds {
   return { environmentId, agentId };
 }
 
+export function readAgentIdsFile(filePath = AGENT_IDS_PATH): AgentIds {
+  return parseAgentIds(JSON.parse(fs.readFileSync(filePath, "utf8")));
+}
+
 const DEFAULT_MODEL = "claude-fable-5";
 
 const ASSISTANT_SYSTEM = `You are a careful, plain-spoken personal finance assistant. Your job is
@@ -166,9 +170,7 @@ async function main() {
       `agent-ids.json already exists — agents are reusable, not per-run.`,
     );
     console.log(`Re-run with --force to re-provision.\n`);
-    printEnvExports(
-      JSON.parse(fs.readFileSync(AGENT_IDS_PATH, "utf8")) as AgentIds,
-    );
+    printEnvExports(readAgentIdsFile());
     return;
   }
 
@@ -221,5 +223,5 @@ export function loadAgentIds(): AgentIds {
         "ANTHROPIC_ENVIRONMENT_ID and ANTHROPIC_AGENT_ID.",
     );
   }
-  return parseAgentIds(JSON.parse(fs.readFileSync(AGENT_IDS_PATH, "utf8")));
+  return readAgentIdsFile();
 }