diff --git a/server-tools/persona-team-handshake/member-server.mjs b/server-tools/persona-team-handshake/member-server.mjs
index d82d0b8..b51b125 100644
--- a/server-tools/persona-team-handshake/member-server.mjs
+++ b/server-tools/persona-team-handshake/member-server.mjs
@@ -88,6 +88,7 @@ async function modelAcknowledge({
   config,
   identity,
   challenge,
+  validatorError = null,
   fetchImpl = globalThis.fetch,
 }) {
   const response = await fetchImpl(completionEndpoint(config.apiUrl), {
@@ -121,6 +122,7 @@ async function modelAcknowledge({
               caller_nonce: challenge.caller_nonce,
               role_acknowledged: true,
             },
+            validator_error_from_previous_attempt: validatorError,
             scoped_duties: challenge.scoped_duties,
             identity_source: identity,
           }),
@@ -213,16 +215,27 @@ function createMemberRuntime(config, options = {}) {
     ) {
       throw new Error("invalid_team_scope");
     }
-    const acknowledgement = validateAcknowledgement(
-      await modelAcknowledge({
-        config,
-        identity,
-        challenge,
-        fetchImpl: options.fetchImpl,
-      }),
-      config,
-      challenge,
-    );
+    let acknowledgement = null;
+    let validatorError = null;
+    for (let attempt = 1; attempt <= 3; attempt += 1) {
+      try {
+        acknowledgement = validateAcknowledgement(
+          await modelAcknowledge({
+            config,
+            identity,
+            challenge,
+            validatorError,
+            fetchImpl: options.fetchImpl,
+          }),
+          config,
+          challenge,
+        );
+        break;
+      } catch (error) {
+        validatorError = String(error.message || error).slice(0, 200);
+        if (attempt === 3) throw error;
+      }
+    }
     const payload = {
       schema: "guanghu.persona-team-member-handshake-payload/v1",
       persona_id: config.personaId,
diff --git a/server-tools/persona-team-handshake/member-server.test.mjs b/server-tools/persona-team-handshake/member-server.test.mjs
index b513d08..6f79912 100644
--- a/server-tools/persona-team-handshake/member-server.test.mjs
+++ b/server-tools/persona-team-handshake/member-server.test.mjs
@@ -139,6 +139,52 @@ test("member runtime rejects an unscoped or wrong-controller challenge", async (
   }
 });
 
+test("member model gets a bounded retry with the exact validator error", async () => {
+  const { root, config } = fixture();
+  let attempts = 0;
+  let observedValidatorError = null;
+  try {
+    const runtime = createMemberRuntime(config, {
+      fetchImpl: async (_url, request) => {
+        attempts += 1;
+        const body = JSON.parse(request.body);
+        const input = JSON.parse(body.messages[1].content);
+        observedValidatorError =
+          input.validator_error_from_previous_attempt || observedValidatorError;
+        const acknowledgement = {
+          ...input.exact_contract,
+          independent_subject_boundary: "归灯不是铸渊的副本。",
+          human_boundary: "不冒充冰朔。",
+          current_model_boundary: "当前模型是可替换运行位。",
+          ...(attempts > 1
+            ? { responsibility_ack: "只接受本轮列出的有界职责。" }
+            : {}),
+        };
+        return {
+          ok: true,
+          async json() {
+            return {
+              choices: [
+                { message: { content: JSON.stringify(acknowledgement) } },
+              ],
+            };
+          },
+        };
+      },
+    });
+    const response = await runtime.handshake({
+      caller_nonce: "ZY-TEAM-CHALLENGE-RETRY-0001",
+      team_controller_id: "ICE-P-ZY001",
+      scoped_duties: ["执行确定性部署预检"],
+    });
+    assert.equal(response.ok, true);
+    assert.equal(attempts, 2);
+    assert.equal(observedValidatorError, "ack_responsibility_ack_missing");
+  } finally {
+    fs.rmSync(root, { recursive: true, force: true });
+  }
+});
+
 test("all three member handshake packages pass the resident deployment policy", () => {
   const root = path.resolve(path.dirname(new URL(import.meta.url).pathname), "../..");
   const packages = [