diff --git a/packages/queue/tests/mcp-tool-schemas.test.ts b/packages/queue/tests/mcp-tool-schemas.test.ts
new file mode 100644
index 0000000..0593cf9
--- /dev/null
+++ b/packages/queue/tests/mcp-tool-schemas.test.ts
@@ -0,0 +1,90 @@
+import { describe, expect, it } from 'vitest';
+
+import {
+  queueClaimToolInputSchema,
+  queueCompleteToolInputSchema,
+  queueFailToolInputSchema,
+  queueGetToolInputSchema,
+  queueHeartbeatToolInputSchema,
+  queueListToolInputSchema,
+  queueReleaseToolInputSchema,
+  queueStatusToolInputSchema,
+} from '../src/mcp-tool-schemas.js';
+
+describe('MCP tool schemas', () => {
+  it('validates queue_list filters', () => {
+    const parsed = queueListToolInputSchema.parse({
+      project: 'queue',
+      mission: 'phase1',
+      status: 'pending',
+    });
+
+    expect(parsed).toEqual({
+      project: 'queue',
+      mission: 'phase1',
+      status: 'pending',
+    });
+  });
+
+  it('requires a taskId for queue_get', () => {
+    expect(() => queueGetToolInputSchema.parse({})).toThrowError();
+  });
+
+  it('requires positive ttlSeconds for queue_claim', () => {
+    expect(() =>
+      queueClaimToolInputSchema.parse({
+        taskId: 'MQ-007',
+        agentId: 'agent-a',
+        ttlSeconds: 0,
+      }),
+    ).toThrowError();
+  });
+
+  it('accepts optional fields for queue_heartbeat and queue_release', () => {
+    const heartbeat = queueHeartbeatToolInputSchema.parse({
+      taskId: 'MQ-007',
+      ttlSeconds: 30,
+    });
+
+    const release = queueReleaseToolInputSchema.parse({
+      taskId: 'MQ-007',
+    });
+
+    expect(heartbeat).toEqual({
+      taskId: 'MQ-007',
+      ttlSeconds: 30,
+    });
+    expect(release).toEqual({
+      taskId: 'MQ-007',
+    });
+  });
+
+  it('validates queue_complete and queue_fail payloads', () => {
+    const complete = queueCompleteToolInputSchema.parse({
+      taskId: 'MQ-007',
+      agentId: 'agent-a',
+      summary: 'done',
+    });
+
+    const fail = queueFailToolInputSchema.parse({
+      taskId: 'MQ-007',
+      reason: 'boom',
+    });
+
+    expect(complete).toEqual({
+      taskId: 'MQ-007',
+      agentId: 'agent-a',
+      summary: 'done',
+    });
+    expect(fail).toEqual({
+      taskId: 'MQ-007',
+      reason: 'boom',
+    });
+  });
+
+  it('accepts an empty payload for queue_status', () => {
+    const parsed = queueStatusToolInputSchema.parse({});
+
+    expect(parsed).toEqual({});
+  });
+});
diff --git a/packages/queue/tests/task-atomic.test.ts b/packages/queue/tests/task-atomic.test.ts
index f931f27..b2a7d1a 100644
--- a/packages/queue/tests/task-atomic.test.ts
+++ b/packages/queue/tests/task-atomic.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from 'vitest';
 
 import {
   RedisTaskRepository,
+  TaskOwnershipError,
   TaskTransitionError,
   type RedisTaskClient,
   type RedisTaskTransaction,
@@ -327,4 +328,32 @@ describe('RedisTaskRepository atomic transitions', () => {
       }),
     ).rejects.toBeInstanceOf(TaskTransitionError);
   });
+
+  it('enforces claim ownership for release and complete', async () => {
+    const [repository] = createRepositoryPair(() => 1_700_000_000_000);
+
+    await repository.create({
+      project: 'queue',
+      mission: 'phase1',
+      taskId: 'MQ-004-OWN',
+      title: 'Ownership checks',
+    });
+
+    await repository.claim('MQ-004-OWN', {
+      agentId: 'agent-a',
+      ttlSeconds: 60,
+    });
+
+    await expect(
+      repository.release('MQ-004-OWN', {
+        agentId: 'agent-b',
+      }),
+    ).rejects.toBeInstanceOf(TaskOwnershipError);
+
+    await expect(
+      repository.complete('MQ-004-OWN', {
+        agentId: 'agent-b',
+      }),
+    ).rejects.toBeInstanceOf(TaskOwnershipError);
+  });
 });