diff --git a/tests/lib/agent-frontmatter.test.mjs b/tests/lib/agent-frontmatter.test.mjs
index 9132f40..5340f9e 100644
--- a/tests/lib/agent-frontmatter.test.mjs
+++ b/tests/lib/agent-frontmatter.test.mjs
@@ -127,3 +127,39 @@ test('non-orchestrator agents do NOT include the Agent tool (no recursive swarmi
     );
   }
 });
+
+// M4 (v5.7.1): examples-relocation invariant. The 34 <example> blocks belong in
+// agent BODIES, not in the always-loaded `description:` frontmatter (voyage
+// launches its agents by name, so the auto-selection examples are cost without
+// function there). This pins the migration: examples cannot regress into
+// frontmatter, and cannot be silently lost during the move.
+function bodyOf(text) {
+  // Slice the file content AFTER the closing frontmatter `---`.
+  // Do NOT split on /^---$/m — a horizontal rule in the body would mis-split.
+  const m = text.match(/^---\r?\n[\s\S]*?\r?\n---\r?\n?/);
+  return m ? text.slice(m[0].length) : text;
+}
+
+test('no agents/*.md frontmatter contains an <example> block (M4: examples live in the body)', () => {
+  for (const f of agentFiles) {
+    const fm = extractFrontmatter(read(`agents/${f}`));
+    assert.ok(fm !== null, `agents/${f}: missing frontmatter`);
+    assert.equal(
+      (fm.match(/<example>/g) || []).length,
+      0,
+      `agents/${f}: <example> blocks must live in the body, not the always-loaded description: frontmatter (M4)`,
+    );
+  }
+});
+
+test('agent bodies retain at least 34 <example> blocks (M4: relocation moves, never deletes)', () => {
+  let total = 0;
+  for (const f of agentFiles) {
+    total += (bodyOf(read(`agents/${f}`)).match(/<example>/g) || []).length;
+  }
+  assert.ok(
+    total >= 34,
+    `expected >= 34 <example> blocks across agent bodies (17 agents x 2), got ${total} ` +
+    `— examples may have been deleted instead of relocated (M4)`,
+  );
+});