diff --git a/actions/setup/js/assign_agent_helpers.cjs b/actions/setup/js/assign_agent_helpers.cjs
index 402a1811e57..a0756435e97 100644
--- a/actions/setup/js/assign_agent_helpers.cjs
+++ b/actions/setup/js/assign_agent_helpers.cjs
@@ -72,34 +72,86 @@ function getAgentName(assignee) {
 
 /**
  * Return list of coding agent bot login names that are currently available as assignable actors
- * in this repository, as determined by checkUserCanBeAssigned.
+ * in this repository, preferring issue-scoped checks when issue/PR context is available
+ * and falling back to repository-scoped checks.
  * @param {string} owner
  * @param {string} repo
+ * @param {number|string|null} [issueNumber]
  * @param {Object} [githubClient] - Authenticated GitHub client (defaults to global github)
  * @returns {Promise<string[]>}
  */
-async function getAvailableAgentLogins(owner, repo, githubClient = github) {
+async function getAvailableAgentLogins(owner, repo, issueNumber = null, githubClient = github) {
   // Deduplicate defensively so future alias additions across agents do not duplicate REST lookups.
   const knownValues = [...new Set(Object.values(AGENT_LOGIN_NAMES).flat())];
   const available = [];
   for (const login of knownValues) {
     try {
-      await githubClient.rest.issues.checkUserCanBeAssigned({
-        owner,
-        repo,
-        assignee: login,
-      });
+      await validateAssigneeAlias(owner, repo, login, issueNumber, githubClient);
       available.push(login);
     } catch (e) {
       const status = e && typeof e === "object" && "status" in e ? e.status : undefined;
       if (status !== 404) {
-        core.debug(`Failed to check assignability for ${login}: ${getErrorMessage(e)}`);
+        core.info(`Failed to check assignability for ${login}: ${getErrorMessage(e)}`);
       }
     }
   }
   return available.sort();
 }
 
+/**
+ * Validate whether an assignee alias can be assigned in the repository context.
+ * Prefer issue-level assignability checks when issue/PR number is available because
+ * some agent bots are not surfaced by repository-scoped checks.
+ * @param {string} owner
+ * @param {string} repo
+ * @param {string} assignee
+ * @param {number|string|null} issueNumber
+ * @param {Object} githubClient
+ */
+async function validateAssigneeAlias(owner, repo, assignee, issueNumber, githubClient) {
+  const parsedIssueNumber = Number(issueNumber);
+  const hasValidIssueNumber = Number.isInteger(parsedIssueNumber) && parsedIssueNumber > 0;
+  const hasIssueScopedRequest = typeof githubClient?.request === "function";
+
+  if (issueNumber && hasValidIssueNumber && hasIssueScopedRequest) {
+    core.info(`Checking assignee alias ${assignee} via issue-scoped endpoint for ${owner}/${repo}#${parsedIssueNumber}`);
+    try {
+      const issueScopedResponse = await githubClient.request("GET /repos/{owner}/{repo}/issues/{issue_number}/assignees/{assignee}", {
+        owner,
+        repo,
+        issue_number: parsedIssueNumber,
+        assignee,
+      });
+      const issueScopedStatus = issueScopedResponse && typeof issueScopedResponse === "object" && "status" in issueScopedResponse ? Number(issueScopedResponse.status) : undefined;
+      if (issueScopedStatus !== undefined && Number.isInteger(issueScopedStatus) && issueScopedStatus >= 200 && issueScopedStatus < 300) {
+        core.info(`Assignee alias ${assignee} is assignable via issue-scoped check`);
+        return;
+      }
+      core.info(`Issue-scoped assignee check returned unexpected response for ${assignee} (status ${issueScopedStatus ?? "unknown"}); falling back to repository-scoped check`);
+    } catch (e) {
+      const status = e && typeof e === "object" && "status" in e ? e.status : undefined;
+      // Some coding-agent bot aliases can return 404 on issue-scoped checks even when
+      // assignment may still succeed; use repository-scoped endpoint as fallback.
+      if (status !== 404 && status !== 422) {
+        core.info(`Issue-scoped assignee check failed for ${assignee} with status ${status ?? "unknown"}: ${getErrorMessage(e)}`);
+        throw e;
+      }
+      core.info(`Issue-scoped assignee check returned ${status} for ${assignee}; falling back to repository-scoped check`);
+    }
+  } else if (issueNumber && !hasValidIssueNumber) {
+    core.info(`Skipping issue-scoped assignee check for ${assignee}: invalid issue number ${String(issueNumber)}`);
+  } else if (issueNumber && !hasIssueScopedRequest) {
+    core.info(`Skipping issue-scoped assignee check for ${assignee}: github client does not support request()`);
+  }
+  core.info(`Checking assignee alias ${assignee} via repository-scoped endpoint for ${owner}/${repo}`);
+  await githubClient.rest.issues.checkUserCanBeAssigned({
+    owner,
+    repo,
+    assignee,
+  });
+  core.info(`Assignee alias ${assignee} is assignable via repository-scoped check`);
+}
+
 /**
  * Return assignable bot logins from the repository assignee list.
  * @param {string} owner
@@ -145,10 +197,11 @@ async function getAssignableBots(owner, repo, githubClient = github) {
  * @param {string} owner - Repository owner
  * @param {string} repo - Repository name
  * @param {string} agentName - Agent name (copilot)
+ * @param {number|string|null} [issueNumber] - Optional issue/PR number for issue-scoped assignability check
  * @param {Object} [githubClient] - Authenticated GitHub client (defaults to global github)
  * @returns {Promise<string|null>} Agent ID or null if not found
  */
-async function findAgent(owner, repo, agentName, githubClient = github) {
+async function findAgent(owner, repo, agentName, issueNumber = null, githubClient = github) {
   const loginNames = getAgentLogins(agentName);
   if (loginNames.length === 0) {
     core.error(`Unknown agent: ${agentName}. Supported agents: ${Object.keys(AGENT_LOGIN_NAMES).join(", ")}`);
@@ -161,11 +214,7 @@ async function findAgent(owner, repo, agentName, githubClient = github) {
   for (const loginName of loginNames) {
     try {
       core.info(`Checking assignee alias: ${loginName}`);
-      await githubClient.rest.issues.checkUserCanBeAssigned({
-        owner,
-        repo,
-        assignee: loginName,
-      });
+      await validateAssigneeAlias(owner, repo, loginName, issueNumber, githubClient);
     } catch (checkError) {
       const errorMessage = getErrorMessage(checkError);
       const status = checkError?.status;
@@ -536,7 +585,7 @@ async function assignAgentToIssueByName(owner, repo, issueNumber, agentName) {
   try {
     // Find agent using the github object authenticated via step-level github-token
     core.info(`Looking for ${agentName} coding agent...`);
-    const agentId = await findAgent(owner, repo, agentName);
+    const agentId = await findAgent(owner, repo, agentName, issueNumber);
     if (!agentId) {
       return { success: false, error: `${agentName} coding agent is not available for this repository` };
     }
diff --git a/actions/setup/js/assign_agent_helpers.test.cjs b/actions/setup/js/assign_agent_helpers.test.cjs
index 5de434d4849..ca0229ef42a 100644
--- a/actions/setup/js/assign_agent_helpers.test.cjs
+++ b/actions/setup/js/assign_agent_helpers.test.cjs
@@ -118,7 +118,38 @@ describe("assign_agent_helpers.cjs", () => {
       const result = await getAvailableAgentLogins("owner", "repo");
 
       expect(result).toEqual([]);
-      expect(mockCore.debug).toHaveBeenCalledWith(expect.stringContaining("Failed to check assignability for copilot-swe-agent"));
+      expect(mockCore.info).toHaveBeenCalledWith(expect.stringContaining("Failed to check assignability for copilot-swe-agent"));
+      expect(mockGithub.rest.issues.checkUserCanBeAssigned).toHaveBeenCalledTimes(5);
+    });
+
+    it("should use issue-scoped assignee checks when issue number is provided", async () => {
+      const err404 = Object.assign(new Error("Not Found"), { status: 404 });
+      mockGithub.request.mockRejectedValueOnce(err404).mockResolvedValueOnce({ status: 204 }).mockRejectedValue(err404);
+      mockGithub.rest.issues.checkUserCanBeAssigned.mockRejectedValue(err404);
+
+      const result = await getAvailableAgentLogins("owner", "repo", 123);
+
+      expect(result).toEqual(["github-copilot-enterprise"]);
+      expect(mockGithub.request).toHaveBeenCalledWith("GET /repos/{owner}/{repo}/issues/{issue_number}/assignees/{assignee}", {
+        owner: "owner",
+        repo: "repo",
+        issue_number: 123,
+        assignee: "copilot-swe-agent",
+      });
+      expect(mockGithub.request).toHaveBeenCalledTimes(5);
+      expect(mockGithub.rest.issues.checkUserCanBeAssigned).toHaveBeenCalledTimes(4);
+    });
+
+    it("should fall back to repository-scoped checks when issue-scoped check returns 422", async () => {
+      const err422 = Object.assign(new Error("Validation Failed"), { status: 422 });
+      const err404 = Object.assign(new Error("Not Found"), { status: 404 });
+      mockGithub.request.mockRejectedValue(err422);
+      mockGithub.rest.issues.checkUserCanBeAssigned.mockRejectedValueOnce(err404).mockResolvedValueOnce({}).mockRejectedValue(err404);
+
+      const result = await getAvailableAgentLogins("owner", "repo", 123);
+
+      expect(result).toEqual(["github-copilot-enterprise"]);
+      expect(mockGithub.request).toHaveBeenCalledTimes(5);
       expect(mockGithub.rest.issues.checkUserCanBeAssigned).toHaveBeenCalledTimes(5);
     });
   });
@@ -210,6 +241,61 @@ describe("assign_agent_helpers.cjs", () => {
       expect(result).toBeNull();
       expect(mockCore.info).toHaveBeenCalledWith(expect.stringContaining("Assignee alias copilot-swe-agent was not assignable"));
     });
+
+    it("should prefer issue-scoped assignee checks when issue number is provided", async () => {
+      const err404 = Object.assign(new Error("Not Found"), { status: 404 });
+      mockGithub.request.mockRejectedValueOnce(err404).mockResolvedValueOnce({ status: 204 });
+      mockGithub.rest.issues.checkUserCanBeAssigned.mockRejectedValueOnce(err404);
+      mockGithub.rest.users.getByUsername.mockResolvedValueOnce({ data: { id: 12345 } });
+
+      const result = await findAgent("owner", "repo", "copilot", 321);
+
+      expect(result).toBe("12345");
+      expect(mockGithub.request).toHaveBeenCalledWith("GET /repos/{owner}/{repo}/issues/{issue_number}/assignees/{assignee}", {
+        owner: "owner",
+        repo: "repo",
+        issue_number: 321,
+        assignee: "copilot-swe-agent",
+      });
+      expect(mockGithub.request).toHaveBeenCalledWith("GET /repos/{owner}/{repo}/issues/{issue_number}/assignees/{assignee}", {
+        owner: "owner",
+        repo: "repo",
+        issue_number: 321,
+        assignee: "github-copilot-enterprise",
+      });
+      expect(mockGithub.rest.issues.checkUserCanBeAssigned).toHaveBeenCalledTimes(1);
+    });
+
+    it("should fall back to repository-scoped checks when issue number is invalid", async () => {
+      const err404 = Object.assign(new Error("Not Found"), { status: 404 });
+      mockGithub.rest.issues.checkUserCanBeAssigned.mockRejectedValue(err404);
+
+      const result = await findAgent("owner", "repo", "copilot", "not-a-number");
+
+      expect(result).toBeNull();
+      expect(mockGithub.request).not.toHaveBeenCalled();
+      expect(mockGithub.rest.issues.checkUserCanBeAssigned).toHaveBeenCalled();
+    });
+
+    it("should fall back to repository-scoped checks when github client has no request method", async () => {
+      const err404 = Object.assign(new Error("Not Found"), { status: 404 });
+      const clientWithoutRequest = {
+        rest: {
+          issues: {
+            checkUserCanBeAssigned: vi.fn().mockRejectedValue(err404),
+            listAssignees: vi.fn().mockResolvedValue({ data: [] }),
+          },
+          users: {
+            getByUsername: vi.fn(),
+          },
+        },
+      };
+
+      const result = await findAgent("owner", "repo", "copilot", 123, clientWithoutRequest);
+
+      expect(result).toBeNull();
+      expect(clientWithoutRequest.rest.issues.checkUserCanBeAssigned).toHaveBeenCalled();
+    });
   });
 
   describe("getIssueDetails", () => {
@@ -400,8 +486,8 @@ describe("assign_agent_helpers.cjs", () => {
 
   describe("assignAgentToIssueByName", () => {
     it("should successfully assign copilot agent", async () => {
-      // findAgent: checkUserCanBeAssigned + getByUsername
-      mockGithub.rest.issues.checkUserCanBeAssigned.mockResolvedValueOnce({});
+      // findAgent: issue-scoped assignee check + getByUsername
+      mockGithub.request.mockResolvedValueOnce({ status: 204 });
       mockGithub.rest.users.getByUsername.mockResolvedValueOnce({ data: { id: 999 } });
       // getIssueDetails
       mockGithub.rest.issues.get.mockResolvedValueOnce({
@@ -427,6 +513,7 @@ describe("assign_agent_helpers.cjs", () => {
 
     it("should return error when agent is not available", async () => {
       const err404 = Object.assign(new Error("Not Found"), { status: 404 });
+      mockGithub.request.mockRejectedValue(err404);
       mockGithub.rest.issues.checkUserCanBeAssigned.mockRejectedValue(err404);
       mockGithub.rest.issues.listAssignees.mockResolvedValue({ data: [] });
 
@@ -438,7 +525,7 @@ describe("assign_agent_helpers.cjs", () => {
 
     it("should report already assigned when agent is in assignees", async () => {
       // findAgent
-      mockGithub.rest.issues.checkUserCanBeAssigned.mockResolvedValueOnce({});
+      mockGithub.request.mockResolvedValueOnce({ status: 204 });
       mockGithub.rest.users.getByUsername.mockResolvedValueOnce({ data: { id: 999 } });
       // getIssueDetails - agent already assigned
       mockGithub.rest.issues.get.mockResolvedValueOnce({
@@ -460,7 +547,7 @@ describe("assign_agent_helpers.cjs", () => {
 
     it("should skip assignment when a secondary copilot alias is already assigned", async () => {
       // findAgent resolves via primary alias with id 999
-      mockGithub.rest.issues.checkUserCanBeAssigned.mockResolvedValueOnce({});
+      mockGithub.request.mockResolvedValueOnce({ status: 204 });
       mockGithub.rest.users.getByUsername.mockResolvedValueOnce({ data: { id: 999 } });
       // getIssueDetails - a secondary alias is the current assignee (different id, same agent)
       mockGithub.rest.issues.get.mockResolvedValueOnce({
@@ -477,7 +564,7 @@ describe("assign_agent_helpers.cjs", () => {
       const result = await assignAgentToIssueByName("owner", "repo", 123, "copilot");
 
       expect(result.success).toBe(true);
-      expect(mockGithub.request).not.toHaveBeenCalled();
+      expect(mockGithub.request).toHaveBeenCalledTimes(1);
       expect(mockCore.info).toHaveBeenCalledWith("copilot is already assigned to issue #123");
     });
   });
diff --git a/actions/setup/js/assign_copilot_to_created_issues.cjs b/actions/setup/js/assign_copilot_to_created_issues.cjs
index 4c900bad6af..17b64980f1d 100644
--- a/actions/setup/js/assign_copilot_to_created_issues.cjs
+++ b/actions/setup/js/assign_copilot_to_created_issues.cjs
@@ -73,7 +73,7 @@ async function main() {
       // Find agent (reuse cached ID for same repo)
       if (!agentId) {
         core.info(`Looking for ${agentName} coding agent...`);
-        agentId = await findAgent(owner, repo, agentName);
+        agentId = await findAgent(owner, repo, agentName, issueNumber);
         if (!agentId) {
           throw new Error(`${ERR_PERMISSION}: ${agentName} coding agent is not available for this repository`);
         }
diff --git a/actions/setup/js/assign_copilot_to_created_issues.test.cjs b/actions/setup/js/assign_copilot_to_created_issues.test.cjs
index aaca4bdb757..937f784685b 100644
--- a/actions/setup/js/assign_copilot_to_created_issues.test.cjs
+++ b/actions/setup/js/assign_copilot_to_created_issues.test.cjs
@@ -82,7 +82,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
         const repo = repoParts[1];
         
         if (!agentId) {
-          agentId = await findAgent(owner, repo, agentName);
+          agentId = await findAgent(owner, repo, agentName, issueNumber);
         }
         
         const issueDetails = await getIssueDetails(owner, repo, issueNumber);
@@ -109,7 +109,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
         const repo = repoParts[1];
         
         if (!agentId) {
-          agentId = await findAgent(owner, repo, agentName);
+          agentId = await findAgent(owner, repo, agentName, issueNumber);
         }
         
         const issueDetails = await getIssueDetails(owner, repo, issueNumber);
@@ -117,7 +117,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
       }
     })()`);
 
-    expect(findAgent).toHaveBeenCalledWith("owner", "repo", "copilot");
+    expect(findAgent).toHaveBeenCalledWith("owner", "repo", "copilot", 123);
     expect(getIssueDetails).toHaveBeenCalledWith("owner", "repo", 123);
     expect(assignAgentToIssue).toHaveBeenCalledWith("ISSUE_123", "AGENT_456", [], "copilot");
   });
@@ -150,7 +150,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
         const repo = repoParts[1];
         
         if (!agentId) {
-          agentId = await findAgent(owner, repo, agentName);
+          agentId = await findAgent(owner, repo, agentName, issueNumber);
         }
         
         const issueDetails = await getIssueDetails(owner, repo, issueNumber);
@@ -216,7 +216,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
           const owner = repoParts[0];
           const repo = repoParts[1];
           
-          const agentId = await findAgent(owner, repo, agentName);
+          const agentId = await findAgent(owner, repo, agentName, issueNumber);
           if (!agentId) {
             throw new Error(\`\${agentName} coding agent is not available for this repository\`);
           }
@@ -251,7 +251,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
         const owner = repoParts[0];
         const repo = repoParts[1];
         
-        const agentId = await findAgent(owner, repo, agentName);
+        const agentId = await findAgent(owner, repo, agentName, issueNumber);
         const issueDetails = await getIssueDetails(owner, repo, issueNumber);
         
         if (issueDetails.currentAssignees.includes(agentId)) {
@@ -292,7 +292,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
           const owner = repoParts[0];
           const repo = repoParts[1];
           
-          const agentId = await findAgent(owner, repo, agentName);
+          const agentId = await findAgent(owner, repo, agentName, issueNumber);
           const issueDetails = await getIssueDetails(owner, repo, issueNumber);
           const success = await assignAgentToIssue(issueDetails.issueId, agentId, issueDetails.currentAssignees, agentName);
           
@@ -324,7 +324,7 @@ describe("assign_copilot_to_created_issues.cjs", () => {
           const owner = repoParts[0];
           const repo = repoParts[1];
           
-          const agentId = await findAgent(owner, repo, agentName);
+          const agentId = await findAgent(owner, repo, agentName, issueNumber);
           await getIssueDetails(owner, repo, issueNumber);
         }
       })()`);
diff --git a/actions/setup/js/assign_to_agent.cjs b/actions/setup/js/assign_to_agent.cjs
index 295b89b2339..9263ec31db2 100644
--- a/actions/setup/js/assign_to_agent.cjs
+++ b/actions/setup/js/assign_to_agent.cjs
@@ -330,7 +330,7 @@ async function main(config = {}) {
       let agentId = agentCache[agentName];
       if (!agentId) {
         core.info(`Looking for ${agentName} coding agent...`);
-        agentId = await findAgent(effectiveOwner, effectiveRepo, agentName, githubClient);
+        agentId = await findAgent(effectiveOwner, effectiveRepo, agentName, issueNumber || pullNumber, githubClient);
         if (!agentId) {
           throw new Error(`${agentName} coding agent is not available for this repository`);
         }
@@ -405,7 +405,7 @@ async function main(config = {}) {
 
       if (isAvailabilityError) {
         try {
-          const available = await getAvailableAgentLogins(effectiveOwner, effectiveRepo, githubClient);
+          const available = await getAvailableAgentLogins(effectiveOwner, effectiveRepo, issueNumber || pullNumber, githubClient);
           if (available.length > 0) errorMessage += ` (available agents: ${available.join(", ")})`;
         } catch (e) {
           core.debug("Failed to enrich unavailable agent message with available list");
diff --git a/actions/setup/js/assign_to_agent.test.cjs b/actions/setup/js/assign_to_agent.test.cjs
index fffbe254250..d2ae930db8f 100644
--- a/actions/setup/js/assign_to_agent.test.cjs
+++ b/actions/setup/js/assign_to_agent.test.cjs
@@ -485,9 +485,10 @@ describe("assign_to_agent", () => {
     expect(mockCore.info).not.toHaveBeenCalledWith(expect.stringContaining("copilot is already assigned to issue #6587"));
     expect(mockCore.info).toHaveBeenCalledWith(expect.stringContaining("Successfully assigned copilot coding agent to issue #6587"));
 
-    expect(mockGithub.request).toHaveBeenCalledTimes(2);
-    expect(mockGithub.request.mock.calls[0][1]).toMatchObject({ owner: "test-owner", repo: "ios-repo" });
-    expect(mockGithub.request.mock.calls[1][1]).toMatchObject({ owner: "test-owner", repo: "android-repo" });
+    const assignmentCalls = mockGithub.request.mock.calls.filter(([route]) => route === "POST /agents/repos/{owner}/{repo}/tasks");
+    expect(assignmentCalls).toHaveLength(2);
+    expect(assignmentCalls[0][1]).toMatchObject({ owner: "test-owner", repo: "ios-repo" });
+    expect(assignmentCalls[1][1]).toMatchObject({ owner: "test-owner", repo: "android-repo" });
     expect(mockSleep).toHaveBeenCalledTimes(1);
     expect(mockSleep).toHaveBeenCalledWith(10000);
 
@@ -542,7 +543,8 @@ describe("assign_to_agent", () => {
     await eval(`(async () => { ${assignToAgentScript}; ${STANDALONE_RUNNER} })()`);
 
     expect(mockCore.info).toHaveBeenCalledWith(expect.stringContaining("copilot is already assigned to issue #6587"));
-    expect(mockGithub.request).toHaveBeenCalledTimes(1);
+    const assignmentCalls = mockGithub.request.mock.calls.filter(([route]) => route === "POST /agents/repos/{owner}/{repo}/tasks");
+    expect(assignmentCalls).toHaveLength(1);
     expect(mockSleep).toHaveBeenCalledTimes(1);
     expect(mockSleep).toHaveBeenCalledWith(10000);
   });
@@ -571,7 +573,8 @@ describe("assign_to_agent", () => {
     await eval(`(async () => { ${assignToAgentScript}; ${STANDALONE_RUNNER} })()`);
 
     expect(mockCore.info).toHaveBeenCalledWith(expect.stringContaining("copilot is already assigned to issue #42"));
-    expect(mockGithub.request).not.toHaveBeenCalled();
+    const assignmentCalls = mockGithub.request.mock.calls.filter(([route]) => route === "POST /agents/repos/{owner}/{repo}/tasks");
+    expect(assignmentCalls).toHaveLength(0);
   });
 
   it("should still skip when agent is already assigned with global pull-request-repo but no per-item override", async () => {
@@ -604,7 +607,8 @@ describe("assign_to_agent", () => {
     expect(mockCore.info).toHaveBeenCalledWith(expect.stringContaining("copilot is already assigned to issue #42"));
     // Should NOT have called the assignment mutation (only 3 GraphQL calls: repo lookup, find agent, get issue)
     expect(mockGithub.rest.repos.get).toHaveBeenCalledTimes(1); // global PR repo lookup
-    expect(mockGithub.request).not.toHaveBeenCalled(); // no assignment since already assigned
+    const assignmentCalls = mockGithub.request.mock.calls.filter(([route]) => route === "POST /agents/repos/{owner}/{repo}/tasks");
+    expect(assignmentCalls).toHaveLength(0); // no assignment since already assigned
     expect(mockCore.setFailed).not.toHaveBeenCalled();
   });
 
@@ -648,13 +652,18 @@ describe("assign_to_agent", () => {
       data: { id: 12345, number: 42, assignees: [], html_url: "", title: "", body: "" },
     });
     // Assignment fails with 502
-    mockGithub.request.mockRejectedValueOnce({
-      response: {
-        status: 502,
-        url: "https://api.github.com/repos/test-owner/test-repo/tasks",
-        headers: { "content-type": "text/html" },
-        data: "<html>\n<head><title>502 Bad Gateway</title></head>\n<body>\n<center><h1>502 Bad Gateway</h1></center>\n<hr><center>nginx</center>\n</body>\n</html>\n",
-      },
+    mockGithub.request.mockImplementation(route => {
+      if (route === "POST /agents/repos/{owner}/{repo}/tasks") {
+        return Promise.reject({
+          response: {
+            status: 502,
+            url: "https://api.github.com/repos/test-owner/test-repo/tasks",
+            headers: { "content-type": "text/html" },
+            data: "<html>\n<head><title>502 Bad Gateway</title></head>\n<body>\n<center><h1>502 Bad Gateway</h1></center>\n<hr><center>nginx</center>\n</body>\n</html>\n",
+          },
+        });
+      }
+      return Promise.resolve({ data: { id: "task-123" } });
     });
 
     await eval(`(async () => { ${assignToAgentScript}; ${STANDALONE_RUNNER} })()`);
@@ -687,7 +696,12 @@ describe("assign_to_agent", () => {
       data: { id: 12345, number: 42, assignees: [], html_url: "", title: "", body: "" },
     });
     // Assignment fails with 502 message
-    mockGithub.request.mockRejectedValueOnce(new Error("502 Bad Gateway"));
+    mockGithub.request.mockImplementation(route => {
+      if (route === "POST /agents/repos/{owner}/{repo}/tasks") {
+        return Promise.reject(new Error("502 Bad Gateway"));
+      }
+      return Promise.resolve({ data: { id: "task-123" } });
+    });
 
     await eval(`(async () => { ${assignToAgentScript}; ${STANDALONE_RUNNER} })()`);
 
@@ -1157,7 +1171,12 @@ describe("assign_to_agent", () => {
 
     // Simulate a different error (not auth-related) during assignment
     const otherError = new Error("Network timeout");
-    mockGithub.request.mockRejectedValue(otherError);
+    mockGithub.request.mockImplementation(route => {
+      if (route === "POST /agents/repos/{owner}/{repo}/tasks") {
+        return Promise.reject(otherError);
+      }
+      return Promise.resolve({ data: { id: "task-123" } });
+    });
 
     await eval(`(async () => { ${assignToAgentScript}; ${STANDALONE_RUNNER} })()`);
 
diff --git a/actions/setup/js/create_issue.cjs b/actions/setup/js/create_issue.cjs
index ac6626f4702..6047b77fbfa 100644
--- a/actions/setup/js/create_issue.cjs
+++ b/actions/setup/js/create_issue.cjs
@@ -1073,7 +1073,7 @@ async function main(config = {}) {
         }
         core.info(`Assigning copilot coding agent to issue #${issue.number} in ${qualifiedItemRepo}...`);
         try {
-          const agentId = await findAgent(repoParts.owner, repoParts.repo, "copilot", copilotClient);
+          const agentId = await findAgent(repoParts.owner, repoParts.repo, "copilot", issue.number, copilotClient);
           if (!agentId) {
             core.warning(`copilot coding agent is not available for ${qualifiedItemRepo}`);
           } else {
diff --git a/actions/setup/js/create_pull_request.cjs b/actions/setup/js/create_pull_request.cjs
index 5e11fd28143..aba54d0c44d 100644
--- a/actions/setup/js/create_pull_request.cjs
+++ b/actions/setup/js/create_pull_request.cjs
@@ -676,7 +676,7 @@ async function main(config = {}) {
     }
     core.info(`Assigning copilot coding agent to fallback issue #${issueNumber} in ${owner}/${repo}...`);
     try {
-      const agentId = await findAgent(owner, repo, "copilot", copilotClient);
+      const agentId = await findAgent(owner, repo, "copilot", issueNumber, copilotClient);
       if (!agentId) {
         core.warning(`copilot coding agent is not available for ${owner}/${repo}`);
         return;
diff --git a/actions/setup/js/create_pull_request.test.cjs b/actions/setup/js/create_pull_request.test.cjs
index 13a774912b9..653744838f4 100644
--- a/actions/setup/js/create_pull_request.test.cjs
+++ b/actions/setup/js/create_pull_request.test.cjs
@@ -3296,8 +3296,10 @@ describe("create_pull_request - copilot assignee on fallback issues", () => {
     expect(issueCall.assignees).not.toContain("copilot");
     expect(issueCall.assignees).toContain("user1");
 
-    // REST task creation should be called once for copilot assignment
-    expect(global.github.request).toHaveBeenCalledTimes(1);
+    // One request for issue-scoped alias validation and one for REST task creation
+    expect(global.github.request).toHaveBeenCalledTimes(2);
+    const requestedRoutes = global.github.request.mock.calls.map(([route]) => route);
+    expect(requestedRoutes).toEqual(expect.arrayContaining(["GET /repos/{owner}/{repo}/issues/{issue_number}/assignees/{assignee}", "POST /agents/repos/{owner}/{repo}/tasks"]));
   });
 
   it("should use configured fallback_labels for fallback issues instead of PR labels", async () => {
diff --git a/actions/setup/js/parse_codex_log.cjs b/actions/setup/js/parse_codex_log.cjs
index 341a9c4ae78..bf76aad5905 100644
--- a/actions/setup/js/parse_codex_log.cjs
+++ b/actions/setup/js/parse_codex_log.cjs
@@ -329,6 +329,8 @@ function isCodexJsonlFormat(lines) {
  * @returns {{markdown: string, logEntries: Array, mcpFailures: Array<string>, maxTurnsHit: boolean}} Parsed log data
  */
 function parseCodexJsonl(logContent) {
+  const DEFAULT_STATUS_ICON = "🔧";
+
   const lines = logContent.split("\n");
   const parsedData = [];
   let usage = null;
@@ -423,10 +425,11 @@ function parseCodexJsonl(logContent) {
   markdown += "## 🤖 Commands and Tools\n\n";
   for (const item of parsedData) {
     if (item.type === "tool") {
-      const [server, toolName] = item.toolName.split("__");
-      markdown += formatCodexToolCall(server, toolName, item.params, item.response, item.statusIcon);
+      const toolNameValue = item.toolName || "unknown-server__unknown-tool";
+      const [server, toolName] = toolNameValue.split("__", 2);
+      markdown += formatCodexToolCall(server, toolName, item.params || "", item.response || "", item.statusIcon || DEFAULT_STATUS_ICON);
     } else if (item.type === "bash") {
-      markdown += formatCodexBashCall(item.content, item.response, item.statusIcon);
+      markdown += formatCodexBashCall(item.content || "", item.response || "", item.statusIcon || DEFAULT_STATUS_ICON);
     }
   }
   markdown += "\n## 📊 Information\n\n";