diff --git a/scanners/lib/active-config-reader.mjs b/scanners/lib/active-config-reader.mjs
index a5a46e1..fc31ee5 100644
--- a/scanners/lib/active-config-reader.mjs
+++ b/scanners/lib/active-config-reader.mjs
@@ -572,14 +572,20 @@ async function countPluginItems(pluginRoot) {
   return counts;
 }
 
-async function listMarkdownFiles(dir) {
+async function listMarkdownFiles(dir, recursive = false) {
   const out = [];
   let entries;
   try { entries = await readdir(dir, { withFileTypes: true }); } catch { return out; }
   for (const e of entries) {
+    const full = join(dir, e.name);
+    if (e.isDirectory()) {
+      // Opt-in recursion (M-BUG-3): CC scans agents dirs recursively, so agents
+      // organized into subfolders must be enumerated too. Other callers stay flat.
+      if (recursive) out.push(...await listMarkdownFiles(full, true));
+      continue;
+    }
     if (!e.isFile()) continue;
     if (!e.name.endsWith('.md')) continue;
-    const full = join(dir, e.name);
     try {
       const s = await stat(full);
       out.push({ path: full, size: s.size });
@@ -662,6 +668,11 @@ export async function enumerateSkills(pluginList = []) {
 // Rules, agents, output styles (v5.6 Foundation enumeration)
 // ─────────────────────────────────────────────────────────────────────────
 
+/** True when `v` is a non-empty, non-whitespace string (a usable frontmatter field). */
+function hasText(v) {
+  return typeof v === 'string' && v.trim().length > 0;
+}
+
 /**
  * Build the project/user/plugin directory list for a per-kind enumerator.
  * Project + user dirs live under `.claude/<dir>`; plugins under each of the
@@ -669,8 +680,16 @@ export async function enumerateSkills(pluginList = []) {
  */
 function configDirs(repoPath, pluginList, subdir, pluginSubdirs = [subdir]) {
   const home = process.env.HOME || process.env.USERPROFILE || '';
-  const dirs = [{ dir: join(repoPath, '.claude', subdir), source: 'project', pluginName: null }];
-  if (home) dirs.push({ dir: join(home, '.claude', subdir), source: 'user', pluginName: null });
+  const projectDir = join(repoPath, '.claude', subdir);
+  const userDir = home ? join(home, '.claude', subdir) : null;
+  const dirs = [];
+  // M-BUG-4: when repoPath === $HOME (the `manifest --global` self-scan), the
+  // project dir resolves to the same path as the user dir. Count it once, as
+  // user scope, instead of enumerating the same directory twice.
+  if (!(userDir && userDir === projectDir)) {
+    dirs.push({ dir: projectDir, source: 'project', pluginName: null });
+  }
+  if (userDir) dirs.push({ dir: userDir, source: 'user', pluginName: null });
   for (const p of pluginList) {
     for (const sub of pluginSubdirs) {
       dirs.push({ dir: join(p.path, sub), source: 'plugin', pluginName: p.name });
@@ -730,8 +749,17 @@ export async function enumerateAgents(repoPath, pluginList = []) {
   const lp = deriveLoadPattern('agent');
   const dirs = configDirs(repoPath, pluginList, 'agents');
   for (const { dir, source, pluginName } of dirs) {
-    const files = await listMarkdownFiles(dir);
+    const files = await listMarkdownFiles(dir, true); // M-BUG-3: CC scans agents dirs recursively
     for (const f of files) {
+      // M-BUG-5: CC registers a subagent only when its frontmatter declares both
+      // `name` and `description` (docs: identity comes only from `name`; both are
+      // required). Frontmatter-less / incomplete files are registration no-ops
+      // that cost zero always-loaded tokens — don't count them as agents.
+      let frontmatter;
+      try {
+        ({ frontmatter } = parseFrontmatter(await readFile(f.path, 'utf-8')));
+      } catch { continue; }
+      if (!hasText(frontmatter && frontmatter.name) || !hasText(frontmatter && frontmatter.description)) continue;
       out.push({
         name: basename(f.path).replace(/\.md$/, ''),
         source,
diff --git a/tests/lib/active-config-reader.test.mjs b/tests/lib/active-config-reader.test.mjs
index 0576727..10c1874 100644
--- a/tests/lib/active-config-reader.test.mjs
+++ b/tests/lib/active-config-reader.test.mjs
@@ -952,6 +952,70 @@ describe('enumerateAgents (v5.6)', () => {
     await mkdir(root, { recursive: true });
     assert.deepEqual(await enumerateAgents(root, []), []);
   });
+
+  // M-BUG-5: CC registers a subagent only when its frontmatter declares both
+  // `name` and `description` (docs: identity comes only from `name`; both are
+  // required). Frontmatter-less / incomplete files are registration no-ops that
+  // cost zero always-loaded tokens — they must NOT be counted as agents.
+  it('M-BUG-5: skips files with no frontmatter at all', async () => {
+    const dir = join(root, '.claude', 'agents');
+    await mkdir(dir, { recursive: true });
+    await writeFile(join(dir, 'reviewer.md'), '---\nname: reviewer\ndescription: reviews code\n---\nbody\n');
+    await writeFile(join(dir, 'not-an-agent.md'), '# Not An Agent\n\nJust a markdown doc, no frontmatter.\n');
+    const agents = await enumerateAgents(root, []);
+    assert.deepEqual(agents.map(a => a.name).sort(), ['reviewer']);
+  });
+
+  it('M-BUG-5: skips files missing name or description', async () => {
+    const dir = join(root, '.claude', 'agents');
+    await mkdir(dir, { recursive: true });
+    await writeFile(join(dir, 'reviewer.md'), '---\nname: reviewer\ndescription: reviews code\n---\nbody\n');
+    await writeFile(join(dir, 'name-only.md'), '---\nname: name-only\n---\nbody\n');
+    await writeFile(join(dir, 'desc-only.md'), '---\ndescription: has no name\n---\nbody\n');
+    await writeFile(join(dir, 'empty-name.md'), '---\nname:\ndescription: blank name\n---\nbody\n');
+    const agents = await enumerateAgents(root, []);
+    assert.deepEqual(agents.map(a => a.name).sort(), ['reviewer']);
+  });
+
+  // M-BUG-3: CC scans agents dirs recursively, so a valid agent in a subfolder
+  // (e.g. agents/review/security.md) is registered and must be counted.
+  it('M-BUG-3: recurses into agent subdirectories', async () => {
+    const sub = join(root, '.claude', 'agents', 'review');
+    await mkdir(sub, { recursive: true });
+    await writeFile(join(sub, 'security.md'), '---\nname: security\ndescription: security review\n---\nbody\n');
+    const agents = await enumerateAgents(root, []);
+    const a = agents.find(x => x.name === 'security');
+    assert.ok(a, 'agent in subdir should be counted');
+    assert.equal(a.source, 'project');
+  });
+});
+
+// M-BUG-4: when repoPath === $HOME (the `manifest --global` self-scan), the
+// project agents dir resolves to the SAME path as the user agents dir. The
+// shared configDirs helper must count it once (as user scope), not twice.
+describe('enumerateAgents — HOME self-scan dedup (M-BUG-4)', () => {
+  let home, originalHome;
+  beforeEach(async () => {
+    home = uniqueDir('agents-home-selfscan');
+    await mkdir(join(home, '.claude', 'agents'), { recursive: true });
+    originalHome = process.env.HOME;
+    process.env.HOME = home;
+  });
+  afterEach(async () => {
+    process.env.HOME = originalHome;
+    await rm(home, { recursive: true, force: true });
+  });
+
+  it('does not double-count user agents when repoPath === HOME', async () => {
+    await writeFile(
+      join(home, '.claude', 'agents', 'solo.md'),
+      '---\nname: solo\ndescription: only one of me\n---\nbody\n',
+    );
+    const agents = await enumerateAgents(home, []);
+    const solos = agents.filter(a => a.name === 'solo');
+    assert.equal(solos.length, 1, 'agent at HOME must be counted once, not twice');
+    assert.equal(solos[0].source, 'user', 'HOME self-scan agents are user scope');
+  });
 });
 
 describe('enumerateOutputStyles (v5.6)', () => {