diff --git a/src/tools/agent-teams/name-validation.test.ts b/src/tools/agent-teams/name-validation.test.ts
index 9dd0b124..9e2c70ca 100644
--- a/src/tools/agent-teams/name-validation.test.ts
+++ b/src/tools/agent-teams/name-validation.test.ts
@@ -1,6 +1,11 @@
 /// <reference types="bun-types" />
 import { describe, expect, test } from "bun:test"
-import { validateAgentName, validateTeamName } from "./name-validation"
+import {
+  validateAgentName,
+  validateAgentNameOrLead,
+  validateTaskId,
+  validateTeamName,
+} from "./name-validation"
 
 describe("agent-teams name validation", () => {
   test("accepts valid team names", () => {
@@ -55,4 +60,19 @@ describe("agent-teams name validation", () => {
     expect(validResult).toBeNull()
     expect(invalidResult).toBe("agent_name_invalid")
   })
+
+  test("allows team-lead for inbox-compatible validation", () => {
+    //#then
+    expect(validateAgentNameOrLead("team-lead")).toBeNull()
+    expect(validateAgentNameOrLead("worker_1")).toBeNull()
+    expect(validateAgentNameOrLead("worker one")).toBe("agent_name_invalid")
+  })
+
+  test("validates task ids", () => {
+    //#then
+    expect(validateTaskId("T-123")).toBeNull()
+    expect(validateTaskId("")).toBe("task_id_required")
+    expect(validateTaskId("../../etc/passwd")).toBe("task_id_invalid")
+    expect(validateTaskId("a".repeat(129))).toBe("task_id_too_long")
+  })
 })
diff --git a/src/tools/agent-teams/name-validation.ts b/src/tools/agent-teams/name-validation.ts
index 10d868fa..dcf3fcf1 100644
--- a/src/tools/agent-teams/name-validation.ts
+++ b/src/tools/agent-teams/name-validation.ts
@@ -1,5 +1,7 @@
 const VALID_NAME_RE = /^[A-Za-z0-9_-]+$/
 const MAX_NAME_LENGTH = 64
+const VALID_TASK_ID_RE = /^[A-Za-z0-9_-]+$/
+const MAX_TASK_ID_LENGTH = 128
 
 function validateName(value: string, label: "team" | "agent"): string | null {
   if (!value || !value.trim()) {
@@ -27,3 +29,26 @@ export function validateAgentName(agentName: string): string | null {
   }
   return validateName(agentName, "agent")
 }
+
+export function validateAgentNameOrLead(agentName: string): string | null {
+  if (agentName === "team-lead") {
+    return null
+  }
+  return validateName(agentName, "agent")
+}
+
+export function validateTaskId(taskId: string): string | null {
+  if (!taskId || !taskId.trim()) {
+    return "task_id_required"
+  }
+
+  if (!VALID_TASK_ID_RE.test(taskId)) {
+    return "task_id_invalid"
+  }
+
+  if (taskId.length > MAX_TASK_ID_LENGTH) {
+    return "task_id_too_long"
+  }
+
+  return null
+}
diff --git a/src/tools/agent-teams/types.test.ts b/src/tools/agent-teams/types.test.ts
new file mode 100644
index 00000000..85291866
--- /dev/null
+++ b/src/tools/agent-teams/types.test.ts
@@ -0,0 +1,29 @@
+/// <reference types="bun-types" />
+import { describe, expect, test } from "bun:test"
+import { TeamTeammateMemberSchema } from "./types"
+
+describe("agent-teams types", () => {
+  test("rejects reserved agentType for teammate schema", () => {
+    //#given
+    const invalidTeammate = {
+      agentId: "worker@team",
+      name: "worker",
+      agentType: "team-lead",
+      model: "native",
+      prompt: "do work",
+      color: "blue",
+      planModeRequired: false,
+      joinedAt: Date.now(),
+      cwd: "/tmp",
+      subscriptions: [],
+      backendType: "native",
+      isActive: false,
+    }
+
+    //#when
+    const result = TeamTeammateMemberSchema.safeParse(invalidTeammate)
+
+    //#then
+    expect(result.success).toBe(false)
+  })
+})
diff --git a/src/tools/agent-teams/types.ts b/src/tools/agent-teams/types.ts
index cfa76d76..3883238c 100644
--- a/src/tools/agent-teams/types.ts
+++ b/src/tools/agent-teams/types.ts
@@ -27,7 +27,9 @@ export const TeamLeadMemberSchema = z.object({
 export const TeamTeammateMemberSchema = z.object({
   agentId: z.string(),
   name: z.string(),
-  agentType: z.string(),
+  agentType: z.string().refine((value) => value !== "team-lead", {
+    message: "agent_type_reserved",
+  }),
   model: z.string(),
   prompt: z.string(),
   color: z.string(),