diff --git a/scripts/lib/session-aliases.js b/scripts/lib/session-aliases.js
index c1d6be6..590c6ce 100644
--- a/scripts/lib/session-aliases.js
+++ b/scripts/lib/session-aliases.js
@@ -310,15 +310,28 @@ function renameAlias(oldAlias, newAlias) {
     return { success: false, error: `Alias '${oldAlias}' not found` };
   }
 
-  if (data.aliases[newAlias]) {
-    return { success: false, error: `Alias '${newAlias}' already exists` };
+  // Validate new alias name (same rules as setAlias)
+  if (!newAlias || newAlias.length === 0) {
+    return { success: false, error: 'New alias name cannot be empty' };
+  }
+
+  if (newAlias.length > 128) {
+    return { success: false, error: 'New alias name cannot exceed 128 characters' };
   }
 
-  // Validate new alias name
   if (!/^[a-zA-Z0-9_-]+$/.test(newAlias)) {
     return { success: false, error: 'New alias name must contain only letters, numbers, dashes, and underscores' };
   }
 
+  const reserved = ['list', 'help', 'remove', 'delete', 'create', 'set'];
+  if (reserved.includes(newAlias.toLowerCase())) {
+    return { success: false, error: `'${newAlias}' is a reserved alias name` };
+  }
+
+  if (data.aliases[newAlias]) {
+    return { success: false, error: `Alias '${newAlias}' already exists` };
+  }
+
   const aliasData = data.aliases[oldAlias];
   delete data.aliases[oldAlias];
 
diff --git a/tests/ci/validators.test.js b/tests/ci/validators.test.js
index c83dd2b..c45e655 100644
--- a/tests/ci/validators.test.js
+++ b/tests/ci/validators.test.js
@@ -470,6 +470,18 @@ function runTests() {
     cleanupTestDir(testDir);
   })) passed++; else failed++;
 
+  if (test('fails on whitespace-only SKILL.md', () => {
+    const testDir = createTestDir();
+    const skillDir = path.join(testDir, 'blank-skill');
+    fs.mkdirSync(skillDir);
+    fs.writeFileSync(path.join(skillDir, 'SKILL.md'), '   \n\t\n  ');
+
+    const result = runValidatorWithDir('validate-skills', 'SKILLS_DIR', testDir);
+    assert.strictEqual(result.code, 1, 'Should reject whitespace-only SKILL.md');
+    assert.ok(result.stderr.includes('Empty file'), 'Should report empty file');
+    cleanupTestDir(testDir);
+  })) passed++; else failed++;
+
   // ==========================================
   // validate-commands.js
   // ==========================================
@@ -673,6 +685,29 @@ function runTests() {
     cleanupTestDir(testDir);
   })) passed++; else failed++;
 
+  if (test('fails on whitespace-only rule file', () => {
+    const testDir = createTestDir();
+    fs.writeFileSync(path.join(testDir, 'blank.md'), '   \n\t\n  ');
+
+    const result = runValidatorWithDir('validate-rules', 'RULES_DIR', testDir);
+    assert.strictEqual(result.code, 1, 'Should reject whitespace-only rule file');
+    assert.ok(result.stderr.includes('Empty'), 'Should report empty file');
+    cleanupTestDir(testDir);
+  })) passed++; else failed++;
+
+  if (test('validates rules in subdirectories recursively', () => {
+    const testDir = createTestDir();
+    const subDir = path.join(testDir, 'sub');
+    fs.mkdirSync(subDir);
+    fs.writeFileSync(path.join(testDir, 'top.md'), '# Top Level Rule');
+    fs.writeFileSync(path.join(subDir, 'nested.md'), '# Nested Rule');
+
+    const result = runValidatorWithDir('validate-rules', 'RULES_DIR', testDir);
+    assert.strictEqual(result.code, 0, 'Should validate nested rules');
+    assert.ok(result.stdout.includes('Validated 2'), 'Should find both rules');
+    cleanupTestDir(testDir);
+  })) passed++; else failed++;
+
   // Summary
   console.log(`\nResults: Passed: ${passed}, Failed: ${failed}`);
   process.exit(failed > 0 ? 1 : 0);
diff --git a/tests/lib/session-aliases.test.js b/tests/lib/session-aliases.test.js
index 913a61b..fa95513 100644
--- a/tests/lib/session-aliases.test.js
+++ b/tests/lib/session-aliases.test.js
@@ -282,6 +282,30 @@ function runTests() {
     assert.strictEqual(result.success, false);
   })) passed++; else failed++;
 
+  if (test('rejects rename to empty string', () => {
+    resetAliases();
+    aliases.setAlias('valid', '/path');
+    const result = aliases.renameAlias('valid', '');
+    assert.strictEqual(result.success, false);
+    assert.ok(result.error.includes('empty'));
+  })) passed++; else failed++;
+
+  if (test('rejects rename to reserved name', () => {
+    resetAliases();
+    aliases.setAlias('valid', '/path');
+    const result = aliases.renameAlias('valid', 'list');
+    assert.strictEqual(result.success, false);
+    assert.ok(result.error.includes('reserved'));
+  })) passed++; else failed++;
+
+  if (test('rejects rename to name exceeding 128 chars', () => {
+    resetAliases();
+    aliases.setAlias('valid', '/path');
+    const result = aliases.renameAlias('valid', 'a'.repeat(129));
+    assert.strictEqual(result.success, false);
+    assert.ok(result.error.includes('128'));
+  })) passed++; else failed++;
+
   // updateAliasTitle tests
   console.log('\nupdateAliasTitle:');