diff --git a/src/cli/commands/tag/__tests__/action.test.ts b/src/cli/commands/tag/__tests__/action.test.ts
deleted file mode 100644
index 6ac044cc5..000000000
--- a/src/cli/commands/tag/__tests__/action.test.ts
+++ /dev/null
@@ -1,184 +0,0 @@
-import { addTag, listTags, removeDefaultTag, removeTag, setDefaultTag } from '../action.js';
-import { beforeEach, describe, expect, it, vi } from 'vitest';
-
-const { mockReadProjectSpec, mockWriteProjectSpec, mockFindConfigRoot } = vi.hoisted(() => ({
-  mockReadProjectSpec: vi.fn(),
-  mockWriteProjectSpec: vi.fn(),
-  mockFindConfigRoot: vi.fn(),
-}));
-
-vi.mock('../../../../lib/index.js', () => ({
-  ConfigIO: class {
-    readProjectSpec = mockReadProjectSpec;
-    writeProjectSpec = mockWriteProjectSpec;
-  },
-  findConfigRoot: mockFindConfigRoot,
-  NoProjectError: class NoProjectError extends Error {
-    constructor() {
-      super('No AgentCore project found');
-      this.name = 'NoProjectError';
-    }
-  },
-}));
-
-const baseSpec = () => ({
-  name: 'TestProject',
-  version: 1,
-  tags: { 'agentcore:created-by': 'agentcore-cli' },
-  runtimes: [
-    {
-      name: 'myAgent',
-      build: 'CodeZip',
-      entrypoint: 'main.py',
-      codeLocation: 'app/myAgent',
-      runtimeVersion: 'python3.13',
-      protocol: 'HTTP',
-    },
-  ],
-  memories: [{ name: 'myMemory', eventExpiryDuration: 30, strategies: [] }],
-  credentials: [],
-  agentCoreGateways: [
-    {
-      name: 'myGateway',
-      targets: [],
-      authorizerType: 'NONE',
-      enableSemanticSearch: true,
-      exceptionLevel: 'NONE',
-    },
-  ],
-});
-
-beforeEach(() => {
-  vi.clearAllMocks();
-  mockFindConfigRoot.mockReturnValue('/fake/config/root');
-  mockReadProjectSpec.mockResolvedValue(baseSpec());
-  mockWriteProjectSpec.mockResolvedValue(undefined);
-});
-
-describe('listTags', () => {
-  it('returns project defaults and all resources with merged tags', async () => {
-    const result = await listTags();
-    expect(result.projectDefaults).toEqual({ 'agentcore:created-by': 'agentcore-cli' });
-    expect(result.resources).toHaveLength(3);
-    expect(result.resources[0]).toEqual({
-      type: 'agent',
-      name: 'myAgent',
-      tags: { 'agentcore:created-by': 'agentcore-cli' },
-    });
-  });
-
-  it('filters by resource ref', async () => {
-    const result = await listTags('agent:myAgent');
-    expect(result.resources).toHaveLength(1);
-    expect(result.resources[0]!.name).toBe('myAgent');
-  });
-
-  it('throws on nonexistent resource', async () => {
-    await expect(listTags('agent:nonexistent')).rejects.toThrow('not found');
-  });
-});
-
-describe('addTag', () => {
-  it('adds tag to agent and writes spec', async () => {
-    const result = await addTag('agent:myAgent', 'env', 'prod');
-    expect(result.success).toBe(true);
-    expect(mockWriteProjectSpec).toHaveBeenCalledTimes(1);
-    const written = mockWriteProjectSpec.mock.calls[0]![0];
-    expect(written.runtimes[0].tags).toEqual({ env: 'prod' });
-  });
-
-  it('adds tag to gateway and writes project spec', async () => {
-    const result = await addTag('gateway:myGateway', 'env', 'prod');
-    expect(result.success).toBe(true);
-    expect(mockWriteProjectSpec).toHaveBeenCalledTimes(1);
-    const written = mockWriteProjectSpec.mock.calls[0]![0];
-    expect(written.agentCoreGateways[0].tags).toEqual({ env: 'prod' });
-  });
-
-  it('throws for invalid resource ref', async () => {
-    await expect(addTag('invalid', 'key', 'value')).rejects.toThrow('Invalid resource reference');
-  });
-
-  it('throws for nonexistent resource', async () => {
-    await expect(addTag('agent:noSuchAgent', 'key', 'value')).rejects.toThrow('not found');
-  });
-
-  it('rejects empty tag key', async () => {
-    await expect(addTag('agent:myAgent', '', 'value')).rejects.toThrow('Invalid tag key');
-  });
-
-  it('rejects tag key exceeding 128 chars', async () => {
-    await expect(addTag('agent:myAgent', 'k'.repeat(129), 'value')).rejects.toThrow('Invalid tag key');
-  });
-
-  it('rejects tag value exceeding 256 chars', async () => {
-    await expect(addTag('agent:myAgent', 'key', 'v'.repeat(257))).rejects.toThrow('Invalid tag value');
-  });
-
-  it('rejects tag key with invalid characters', async () => {
-    await expect(addTag('agent:myAgent', 'key\x00bad', 'value')).rejects.toThrow('Invalid tag key');
-  });
-
-  it('rejects tag value with invalid characters', async () => {
-    await expect(addTag('agent:myAgent', 'key', 'value\x00bad')).rejects.toThrow('Invalid tag value');
-  });
-
-  it('rejects agentcore: prefixed keys', async () => {
-    await expect(addTag('agent:myAgent', 'agentcore:custom', 'value')).rejects.toThrow('managed by the system');
-  });
-});
-
-describe('removeTag', () => {
-  it('removes tag from agent', async () => {
-    const spec = baseSpec();
-    (spec.runtimes[0] as Record<string, unknown>).tags = { env: 'prod', team: 'a' };
-    mockReadProjectSpec.mockResolvedValue(spec);
-
-    const result = await removeTag('agent:myAgent', 'env');
-    expect(result.success).toBe(true);
-    const written = mockWriteProjectSpec.mock.calls[0]![0];
-    expect(written.runtimes[0].tags).toEqual({ team: 'a' });
-  });
-
-  it('throws when key not found with hint about defaults', async () => {
-    await expect(removeTag('agent:myAgent', 'nonexistent')).rejects.toThrow('remove-defaults');
-  });
-
-  it('rejects agentcore: prefixed keys', async () => {
-    await expect(removeTag('agent:myAgent', 'agentcore:created-by')).rejects.toThrow('managed by the system');
-  });
-});
-
-describe('setDefaultTag', () => {
-  it('sets project-level default tag', async () => {
-    const result = await setDefaultTag('team', 'platform');
-    expect(result.success).toBe(true);
-    const written = mockWriteProjectSpec.mock.calls[0]![0];
-    expect(written.tags).toEqual({ 'agentcore:created-by': 'agentcore-cli', team: 'platform' });
-  });
-
-  it('rejects agentcore: prefixed keys', async () => {
-    await expect(setDefaultTag('agentcore:custom', 'value')).rejects.toThrow('managed by the system');
-  });
-});
-
-describe('removeDefaultTag', () => {
-  it('rejects removal of agentcore: prefixed system tags', async () => {
-    await expect(removeDefaultTag('agentcore:created-by')).rejects.toThrow('managed by the system');
-  });
-
-  it('removes user-defined project-level default tag', async () => {
-    const spec = baseSpec();
-    (spec.tags as Record<string, string>).team = 'platform';
-    mockReadProjectSpec.mockResolvedValue(spec);
-
-    const result = await removeDefaultTag('team');
-    expect(result.success).toBe(true);
-    const written = mockWriteProjectSpec.mock.calls[0]![0];
-    expect(written.tags).toEqual({ 'agentcore:created-by': 'agentcore-cli' });
-  });
-
-  it('throws when key not found', async () => {
-    await expect(removeDefaultTag('nonexistent')).rejects.toThrow('not found');
-  });
-});
diff --git a/src/cli/commands/tag/action.ts b/src/cli/commands/tag/action.ts
deleted file mode 100644
index 3cedbc149..000000000
--- a/src/cli/commands/tag/action.ts
+++ /dev/null
@@ -1,221 +0,0 @@
-import { ConfigIO, NoProjectError, findConfigRoot } from '../../../lib';
-import { TagKeySchema, TagValueSchema } from '../../../schema/schemas/primitives/tags';
-import type { ResourceRef, ResourceTagInfo, TagListResult, TaggableResourceType } from './types';
-import { TAGGABLE_RESOURCE_TYPES } from './types';
-
-function getConfigIO(): ConfigIO {
-  const configRoot = findConfigRoot();
-  if (!configRoot) {
-    throw new NoProjectError();
-  }
-  return new ConfigIO({ baseDir: configRoot });
-}
-
-function parseResourceRef(ref: string): ResourceRef {
-  const colonIndex = ref.indexOf(':');
-  if (colonIndex === -1) {
-    throw new Error(`Invalid resource reference "${ref}". Expected format: type:name (e.g., agent:MyAgent)`);
-  }
-  const type = ref.substring(0, colonIndex) as TaggableResourceType;
-  const name = ref.substring(colonIndex + 1);
-
-  if (!TAGGABLE_RESOURCE_TYPES.includes(type)) {
-    throw new Error(`Invalid resource type "${type}". Taggable types: ${TAGGABLE_RESOURCE_TYPES.join(', ')}`);
-  }
-  if (!name) {
-    throw new Error(`Resource name is required in reference "${ref}".`);
-  }
-  return { type, name };
-}
-
-export async function listTags(resourceFilter?: string): Promise<TagListResult> {
-  const configIO = getConfigIO();
-  const spec = await configIO.readProjectSpec();
-  const projectDefaults = spec.tags ?? {};
-  const resources: ResourceTagInfo[] = [];
-
-  // Collect agents
-  for (const agent of spec.runtimes ?? []) {
-    resources.push({
-      type: 'agent',
-      name: agent.name,
-      tags: { ...projectDefaults, ...(agent.tags ?? {}) },
-    });
-  }
-
-  // Collect memories
-  for (const memory of spec.memories ?? []) {
-    resources.push({
-      type: 'memory',
-      name: memory.name,
-      tags: { ...projectDefaults, ...(memory.tags ?? {}) },
-    });
-  }
-
-  // Collect gateways (now in project spec after mcp.json merge)
-  for (const gateway of spec.agentCoreGateways ?? []) {
-    resources.push({
-      type: 'gateway',
-      name: gateway.name,
-      tags: { ...projectDefaults, ...(gateway.tags ?? {}) },
-    });
-  }
-
-  // Collect evaluators
-  for (const evaluator of spec.evaluators ?? []) {
-    resources.push({
-      type: 'evaluator',
-      name: evaluator.name,
-      tags: { ...projectDefaults, ...(evaluator.tags ?? {}) },
-    });
-  }
-
-  // Collect policy engines
-  for (const engine of spec.policyEngines ?? []) {
-    resources.push({
-      type: 'policy-engine',
-      name: engine.name,
-      tags: { ...projectDefaults, ...(engine.tags ?? {}) },
-    });
-  }
-
-  // Collect online eval configs
-  for (const config of spec.onlineEvalConfigs ?? []) {
-    resources.push({
-      type: 'online-eval-config',
-      name: config.name,
-      tags: { ...projectDefaults, ...(config.tags ?? {}) },
-    });
-  }
-
-  // Apply filter if specified
-  if (resourceFilter) {
-    const ref = parseResourceRef(resourceFilter);
-    const filtered = resources.filter(r => r.type === ref.type && r.name === ref.name);
-    if (filtered.length === 0) {
-      throw new Error(`Resource "${resourceFilter}" not found.`);
-    }
-    return { projectDefaults, resources: filtered };
-  }
-
-  return { projectDefaults, resources };
-}
-
-function validateTagKeyValue(key: string, value: string): void {
-  if (key.startsWith('agentcore:')) {
-    throw new Error('Tag keys starting with "agentcore:" are managed by the system and cannot be modified.');
-  }
-  const keyResult = TagKeySchema.safeParse(key);
-  if (!keyResult.success) {
-    throw new Error(`Invalid tag key: ${keyResult.error.issues[0]?.message ?? 'validation failed'}`);
-  }
-  const valueResult = TagValueSchema.safeParse(value);
-  if (!valueResult.success) {
-    throw new Error(`Invalid tag value: ${valueResult.error.issues[0]?.message ?? 'validation failed'}`);
-  }
-}
-
-export async function addTag(resourceRefStr: string, key: string, value: string): Promise<{ success: boolean }> {
-  validateTagKeyValue(key, value);
-  const ref = parseResourceRef(resourceRefStr);
-  const configIO = getConfigIO();
-
-  if (
-    ref.type === 'agent' ||
-    ref.type === 'memory' ||
-    ref.type === 'evaluator' ||
-    ref.type === 'policy-engine' ||
-    ref.type === 'online-eval-config'
-  ) {
-    const spec = await configIO.readProjectSpec();
-    let collection: { name: string; tags?: Record<string, string> }[] | undefined;
-    if (ref.type === 'agent') collection = spec.runtimes;
-    else if (ref.type === 'memory') collection = spec.memories;
-    else if (ref.type === 'evaluator') collection = spec.evaluators;
-    else if (ref.type === 'policy-engine') collection = spec.policyEngines;
-    else if (ref.type === 'online-eval-config') collection = spec.onlineEvalConfigs;
-
-    const resource = (collection ?? []).find(r => r.name === ref.name);
-    if (!resource) {
-      throw new Error(`${ref.type} "${ref.name}" not found in project.`);
-    }
-    resource.tags = { ...(resource.tags ?? {}), [key]: value };
-    await configIO.writeProjectSpec(spec);
-  } else if (ref.type === 'gateway') {
-    const spec = await configIO.readProjectSpec();
-    const gateway = spec.agentCoreGateways.find(g => g.name === ref.name);
-    if (!gateway) {
-      throw new Error(`gateway "${ref.name}" not found in project.`);
-    }
-    gateway.tags = { ...(gateway.tags ?? {}), [key]: value };
-    await configIO.writeProjectSpec(spec);
-  }
-
-  return { success: true };
-}
-
-export async function removeTag(resourceRefStr: string, key: string): Promise<{ success: boolean }> {
-  if (key.startsWith('agentcore:')) {
-    throw new Error('Tag keys starting with "agentcore:" are managed by the system and cannot be modified.');
-  }
-  const ref = parseResourceRef(resourceRefStr);
-  const configIO = getConfigIO();
-  const spec = await configIO.readProjectSpec();
-
-  let collection: { name: string; tags?: Record<string, string> }[] | undefined;
-  if (ref.type === 'agent') collection = spec.runtimes;
-  else if (ref.type === 'memory') collection = spec.memories;
-  else if (ref.type === 'evaluator') collection = spec.evaluators;
-  else if (ref.type === 'policy-engine') collection = spec.policyEngines;
-  else if (ref.type === 'online-eval-config') collection = spec.onlineEvalConfigs;
-  else if (ref.type === 'gateway') collection = spec.agentCoreGateways;
-
-  const resource = (collection ?? []).find(r => r.name === ref.name);
-  if (!resource) {
-    throw new Error(`${ref.type} "${ref.name}" not found in project.`);
-  }
-  if (!resource.tags || !(key in resource.tags)) {
-    throw new Error(
-      `Tag key "${key}" not found on ${ref.type} "${ref.name}". ` +
-        `If this is an inherited project default, use "tag remove-defaults --key ${key}" instead.`
-    );
-  }
-  delete resource.tags[key];
-  if (Object.keys(resource.tags).length === 0) {
-    resource.tags = undefined;
-  }
-  await configIO.writeProjectSpec(spec);
-
-  return { success: true };
-}
-
-export async function setDefaultTag(key: string, value: string): Promise<{ success: boolean }> {
-  validateTagKeyValue(key, value);
-  const configIO = getConfigIO();
-  const spec = await configIO.readProjectSpec();
-  spec.tags = { ...(spec.tags ?? {}), [key]: value };
-  await configIO.writeProjectSpec(spec);
-  return { success: true };
-}
-
-export async function removeDefaultTag(key: string): Promise<{ success: boolean }> {
-  if (key.startsWith('agentcore:')) {
-    throw new Error('Tag keys starting with "agentcore:" are managed by the system and cannot be modified.');
-  }
-  const configIO = getConfigIO();
-  const spec = await configIO.readProjectSpec();
-  if (!spec.tags || !(key in spec.tags)) {
-    throw new Error(`Default tag key "${key}" not found.`);
-  }
-  delete spec.tags[key];
-  if (Object.keys(spec.tags).length === 0) {
-    spec.tags = undefined;
-  }
-  await configIO.writeProjectSpec(spec);
-  return { success: true };
-}
-
-export async function getAvailableResources(): Promise<string[]> {
-  const result = await listTags();
-  return result.resources.map(r => `${r.type}:${r.name}`);
-}
diff --git a/src/cli/commands/tag/types.ts b/src/cli/commands/tag/types.ts
deleted file mode 100644
index a1d000d38..000000000
--- a/src/cli/commands/tag/types.ts
+++ /dev/null
@@ -1,32 +0,0 @@
-export type TaggableResourceType =
-  | 'agent'
-  | 'memory'
-  | 'gateway'
-  | 'evaluator'
-  | 'policy-engine'
-  | 'online-eval-config';
-
-export const TAGGABLE_RESOURCE_TYPES: TaggableResourceType[] = [
-  'agent',
-  'memory',
-  'gateway',
-  'evaluator',
-  'policy-engine',
-  'online-eval-config',
-];
-
-export interface ResourceRef {
-  type: TaggableResourceType;
-  name: string;
-}
-
-export interface ResourceTagInfo {
-  type: TaggableResourceType;
-  name: string;
-  tags: Record<string, string>;
-}
-
-export interface TagListResult {
-  projectDefaults: Record<string, string>;
-  resources: ResourceTagInfo[];
-}