diff --git a/src/php/UnifiedSnippets/Adapters/DB_Scanner_Adapter.php b/src/php/UnifiedSnippets/Adapters/DB_Scanner_Adapter.php
index c429c30e..2d601c87 100644
--- a/src/php/UnifiedSnippets/Adapters/DB_Scanner_Adapter.php
+++ b/src/php/UnifiedSnippets/Adapters/DB_Scanner_Adapter.php
@@ -13,14 +13,36 @@
  */
 abstract class DB_Scanner_Adapter extends Scanner_Base {
 
+	/**
+	 * The wrapped importer that reads rows from the source plugin's storage.
+	 *
+	 * @var Plugin_Importer
+	 */
 	protected Plugin_Importer $importer;
 
+	/**
+	 * Class constructor.
+	 *
+	 * @param Plugin_Importer|null $importer Optional importer override, primarily for testing.
+	 *                                       When null, the concrete subclass creates one via
+	 *                                       {@see self::create_importer()}.
+	 */
 	public function __construct( ?Plugin_Importer $importer = null ) {
 		$this->importer = $importer ?? $this->create_importer();
 	}
 
+	/**
+	 * Construct the {@see Plugin_Importer} this adapter wraps.
+	 *
+	 * @return Plugin_Importer
+	 */
 	abstract protected function create_importer(): Plugin_Importer;
 
+	/**
+	 * The source plugin's storage table name (without the WordPress table prefix).
+	 *
+	 * @return string
+	 */
 	abstract protected function get_table_name(): string;
 
 	/**
@@ -34,10 +56,19 @@ abstract protected function get_table_name(): string;
 	 */
 	abstract protected function map_row( array $row ): ?array;
 
+	/**
+	 * {@inheritDoc}
+	 *
+	 * Delegates to the wrapped importer's `is_active()` so the adapter is available exactly
+	 * when the source plugin would be importable.
+	 */
 	public function is_available(): bool {
 		return (bool) call_user_func( [ get_class( $this->importer ), 'is_active' ] );
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	public function scan(): array {
 		if ( ! $this->is_available() ) {
 			return [];
@@ -59,6 +90,13 @@ public function scan(): array {
 		return $snippets;
 	}
 
+	/**
+	 * Merge per-row field overrides on top of adapter-wide defaults.
+	 *
+	 * @param array<string, mixed> $fields Row-specific overrides from {@see self::map_row()}.
+	 *
+	 * @return array<string, mixed>
+	 */
 	private function with_defaults( array $fields ): array {
 		return array_merge(
 			[
diff --git a/src/php/UnifiedSnippets/Model/Discovered_Snippet.php b/src/php/UnifiedSnippets/Model/Discovered_Snippet.php
index 1d0b9969..0e5cf5e1 100644
--- a/src/php/UnifiedSnippets/Model/Discovered_Snippet.php
+++ b/src/php/UnifiedSnippets/Model/Discovered_Snippet.php
@@ -34,8 +34,14 @@ class Discovered_Snippet extends Model {
 	private const VALID_TYPES = [ 'php', 'css', 'js', 'html', 'config', 'mixed' ];
 
 	private const VALID_SOURCE_TYPES = [
-		'theme', 'child-theme', 'plugin', 'builder',
-		'core', 'server', 'customizer', 'mu-plugin',
+		'theme',
+		'child-theme',
+		'plugin',
+		'builder',
+		'core',
+		'server',
+		'customizer',
+		'mu-plugin',
 	];
 
 	private const VALID_RISK_LEVELS = [ 'low', 'medium', 'high' ];
@@ -146,13 +152,16 @@ protected function prepare_risk_level( string $risk_level ): string {
 	 * @return string SHA-256 hash.
 	 */
 	public function generate_hash(): string {
-		$key = implode( '|', [
-			$this->scanner_id,
-			$this->source_type,
-			$this->source_path,
-			$this->line_start,
-			$this->line_end,
-		] );
+		$key = implode(
+            '|',
+            [
+				$this->scanner_id,
+				$this->source_type,
+				$this->source_path,
+				$this->line_start,
+				$this->line_end,
+			]
+        );
 
 		$this->hash = hash( 'sha256', $key );
 
diff --git a/src/php/UnifiedSnippets/REST/Scan_REST_Controller.php b/src/php/UnifiedSnippets/REST/Scan_REST_Controller.php
index df078a1d..5dab5702 100644
--- a/src/php/UnifiedSnippets/REST/Scan_REST_Controller.php
+++ b/src/php/UnifiedSnippets/REST/Scan_REST_Controller.php
@@ -30,11 +30,15 @@ class Scan_REST_Controller extends REST_Controller {
 	public const BASE_ROUTE = 'scan';
 
 	/**
+	 * Registry of available scanners, used to look up and run scanners by ID.
+	 *
 	 * @var Scanner_Registry
 	 */
 	private Scanner_Registry $registry;
 
 	/**
+	 * Persisted scan results store, used to save new scans and read prior results.
+	 *
 	 * @var Scan_Results_Store
 	 */
 	private Scan_Results_Store $store;
@@ -236,10 +240,12 @@ public function run_single_scanner( WP_REST_Request $request ) {
 
 		$this->store->merge_scanner_results( $scanner_id, $snippets );
 
-		return rest_ensure_response( [
-			'scanner_id' => $scanner_id,
-			'count'      => count( $snippets ),
-		] );
+		return rest_ensure_response(
+            [
+				'scanner_id' => $scanner_id,
+				'count'      => count( $snippets ),
+			]
+        );
 	}
 
 	/**
@@ -263,16 +269,18 @@ public function get_results( WP_REST_Request $request ): WP_REST_Response {
 
 		$metadata = $this->store->get_metadata();
 
-		return rest_ensure_response( [
-			'scan_date'   => $metadata['scan_date'],
-			'scanners'    => $metadata['scanners'],
-			'total_count' => $metadata['total_count'],
-			'count'       => count( $snippets ),
-			'snippets'    => array_map(
-				static fn( $s ) => $s->to_array(),
-				array_values( $snippets )
-			),
-		] );
+		return rest_ensure_response(
+            [
+				'scan_date'   => $metadata['scan_date'],
+				'scanners'    => $metadata['scanners'],
+				'total_count' => $metadata['total_count'],
+				'count'       => count( $snippets ),
+				'snippets'    => array_map(
+					static fn( $s ) => $s->to_array(),
+					array_values( $snippets )
+				),
+			]
+        );
 	}
 
 	/**
@@ -281,9 +289,11 @@ public function get_results( WP_REST_Request $request ): WP_REST_Response {
 	 * @return WP_REST_Response
 	 */
 	public function list_scanners(): WP_REST_Response {
-		return rest_ensure_response( [
-			'scanners' => $this->registry->get_scanner_info(),
-		] );
+		return rest_ensure_response(
+            [
+				'scanners' => $this->registry->get_scanner_info(),
+			]
+        );
 	}
 
 	/**
@@ -301,11 +311,13 @@ public function get_changes(): WP_REST_Response {
 			$items
 		);
 
-		return rest_ensure_response( [
-			'new'      => $serialize( $changes['new'] ),
-			'modified' => $serialize( $changes['modified'] ),
-			'removed'  => $serialize( $changes['removed'] ),
-		] );
+		return rest_ensure_response(
+            [
+				'new'      => $serialize( $changes['new'] ),
+				'modified' => $serialize( $changes['modified'] ),
+				'removed'  => $serialize( $changes['removed'] ),
+			]
+        );
 	}
 
 	/**
diff --git a/src/php/UnifiedSnippets/Scanners/Header_Footer_Code_Manager_Scanner.php b/src/php/UnifiedSnippets/Scanners/Header_Footer_Code_Manager_Scanner.php
index d42b9998..0382d4b7 100644
--- a/src/php/UnifiedSnippets/Scanners/Header_Footer_Code_Manager_Scanner.php
+++ b/src/php/UnifiedSnippets/Scanners/Header_Footer_Code_Manager_Scanner.php
@@ -17,22 +17,39 @@
  */
 class Header_Footer_Code_Manager_Scanner extends DB_Scanner_Adapter {
 
+	/**
+	 * {@inheritDoc}
+	 */
 	public function get_id(): string {
 		return 'hfcm';
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	public function get_label(): string {
 		return __( 'Header Footer Code Manager', 'code-snippets' );
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	protected function create_importer(): Plugin_Importer {
 		return new Header_Footer_Code_Manager_Plugin_Importer();
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	protected function get_table_name(): string {
 		return 'hfcm_scripts';
 	}
 
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @param array<string, mixed> $row Raw HFCM row from `{prefix}hfcm_scripts`.
+	 */
 	protected function map_row( array $row ): ?array {
 		$code = (string) ( $row['snippet'] ?? '' );
 
diff --git a/src/php/UnifiedSnippets/Scanners/Insert_Headers_And_Footers_Scanner.php b/src/php/UnifiedSnippets/Scanners/Insert_Headers_And_Footers_Scanner.php
index 652abf4e..d57f9503 100644
--- a/src/php/UnifiedSnippets/Scanners/Insert_Headers_And_Footers_Scanner.php
+++ b/src/php/UnifiedSnippets/Scanners/Insert_Headers_And_Footers_Scanner.php
@@ -19,22 +19,39 @@ class Insert_Headers_And_Footers_Scanner extends DB_Scanner_Adapter {
 
 	private const SUPPORTED_CODE_TYPES = [ 'php', 'css', 'js', 'html', 'universal' ];
 
+	/**
+	 * {@inheritDoc}
+	 */
 	public function get_id(): string {
 		return 'wpcode';
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	public function get_label(): string {
 		return __( 'WPCode (Insert Headers and Footers)', 'code-snippets' );
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	protected function create_importer(): Plugin_Importer {
 		return new Insert_Headers_And_Footers_Plugin_Importer();
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	protected function get_table_name(): string {
 		return 'wpcode_snippets';
 	}
 
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @param array<string, mixed> $row Raw WPCode row from `wpcode` custom posts.
+	 */
 	protected function map_row( array $row ): ?array {
 		$code_type = (string) ( $row['code_type'] ?? '' );
 
diff --git a/src/php/UnifiedSnippets/Scanners/Insert_PHP_Code_Snippet_Scanner.php b/src/php/UnifiedSnippets/Scanners/Insert_PHP_Code_Snippet_Scanner.php
index f47a2d90..2666068b 100644
--- a/src/php/UnifiedSnippets/Scanners/Insert_PHP_Code_Snippet_Scanner.php
+++ b/src/php/UnifiedSnippets/Scanners/Insert_PHP_Code_Snippet_Scanner.php
@@ -17,26 +17,48 @@
  */
 class Insert_PHP_Code_Snippet_Scanner extends DB_Scanner_Adapter {
 
+	/**
+	 * {@inheritDoc}
+	 */
 	public function get_id(): string {
 		return 'insert-php-code-snippet';
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	public function get_label(): string {
 		return __( 'Insert PHP Code Snippet', 'code-snippets' );
 	}
 
+	/**
+	 * {@inheritDoc}
+	 *
+	 * Discovered snippets execute arbitrary PHP, so the default risk is raised to 'high'.
+	 */
 	public function get_risk_level(): string {
 		return 'high';
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	protected function create_importer(): Plugin_Importer {
 		return new Insert_PHP_Code_Snippet_Plugin_Importer();
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
 	protected function get_table_name(): string {
 		return 'xyz_ips_short_code';
 	}
 
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @param array<string, mixed> $row Raw Insert PHP Code Snippet row from `{prefix}xyz_ips_short_code`.
+	 */
 	protected function map_row( array $row ): ?array {
 		$code = (string) ( $row['content'] ?? '' );
 
diff --git a/tests/phpunit/fakes/Fake_Hfcm_Importer.php b/tests/phpunit/fakes/Fake_Hfcm_Importer.php
index ce71c374..dd113aef 100644
--- a/tests/phpunit/fakes/Fake_Hfcm_Importer.php
+++ b/tests/phpunit/fakes/Fake_Hfcm_Importer.php
@@ -4,12 +4,37 @@
 
 use Code_Snippets\REST_API\Import\Plugins\Header_Footer_Code_Manager_Plugin_Importer;
 
+/**
+ * Test double for {@see Header_Footer_Code_Manager_Plugin_Importer}.
+ *
+ * Always reports the source plugin as active and returns whatever rows the test assigns to
+ * the public {@see self::$rows} property, so HFCM scanner tests do not need a real install.
+ */
 class Fake_Hfcm_Importer extends Header_Footer_Code_Manager_Plugin_Importer {
 
+	/**
+	 * Rows the fake importer should return from {@see self::get_data()}.
+	 *
+	 * @var array<int, array<string, mixed>>
+	 */
+	public array $rows = [];
+
+	/**
+	 * Force the source plugin to look active.
+	 *
+	 * @return bool Always true.
+	 */
 	public static function is_active(): bool {
 		return true;
 	}
 
+	/**
+	 * Return the rows assigned to this fake.
+	 *
+	 * @param array<int|string> $ids_to_import Unused; satisfies the parent signature.
+	 *
+	 * @return array<int, array<string, mixed>>
+	 */
 	public function get_data( array $ids_to_import = [] ): array {
 		return $this->rows;
 	}
diff --git a/tests/phpunit/fakes/Fake_Ihaf_Importer.php b/tests/phpunit/fakes/Fake_Ihaf_Importer.php
index f17e709e..d1d3f55c 100644
--- a/tests/phpunit/fakes/Fake_Ihaf_Importer.php
+++ b/tests/phpunit/fakes/Fake_Ihaf_Importer.php
@@ -4,14 +4,37 @@
 
 use Code_Snippets\REST_API\Import\Plugins\Insert_Headers_And_Footers_Plugin_Importer;
 
+/**
+ * Test double for {@see Insert_Headers_And_Footers_Plugin_Importer} (WPCode).
+ *
+ * Always reports the source plugin as active and returns whatever rows the test assigns to
+ * the public {@see self::$rows} property, so WPCode scanner tests do not need a real install.
+ */
 class Fake_Ihaf_Importer extends Insert_Headers_And_Footers_Plugin_Importer {
 
+	/**
+	 * Rows the fake importer should return from {@see self::get_data()}.
+	 *
+	 * @var array<int, array<string, mixed>>
+	 */
 	public array $rows = [];
 
+	/**
+	 * Force the source plugin to look active.
+	 *
+	 * @return bool Always true.
+	 */
 	public static function is_active(): bool {
 		return true;
 	}
 
+	/**
+	 * Return the rows assigned to this fake.
+	 *
+	 * @param array<int|string> $ids_to_import Unused; satisfies the parent signature.
+	 *
+	 * @return array<int, array<string, mixed>>
+	 */
 	public function get_data( array $ids_to_import = [] ): array {
 		return $this->rows;
 	}
diff --git a/tests/phpunit/fakes/Fake_Ipcs_Importer.php b/tests/phpunit/fakes/Fake_Ipcs_Importer.php
index 7d999c22..233cbe61 100644
--- a/tests/phpunit/fakes/Fake_Ipcs_Importer.php
+++ b/tests/phpunit/fakes/Fake_Ipcs_Importer.php
@@ -4,14 +4,38 @@
 
 use Code_Snippets\REST_API\Import\Plugins\Insert_PHP_Code_Snippet_Plugin_Importer;
 
+/**
+ * Test double for {@see Insert_PHP_Code_Snippet_Plugin_Importer}.
+ *
+ * Always reports the source plugin as active and returns whatever rows the test assigns to
+ * the public {@see self::$rows} property, so Insert PHP Code Snippet scanner tests do not
+ * need a real install.
+ */
 class Fake_Ipcs_Importer extends Insert_PHP_Code_Snippet_Plugin_Importer {
 
+	/**
+	 * Rows the fake importer should return from {@see self::get_data()}.
+	 *
+	 * @var array<int, array<string, mixed>|object>
+	 */
 	public array $rows = [];
 
+	/**
+	 * Force the source plugin to look active.
+	 *
+	 * @return bool Always true.
+	 */
 	public static function is_active(): bool {
 		return true;
 	}
 
+	/**
+	 * Return the rows assigned to this fake.
+	 *
+	 * @param array<int|string> $ids_to_import Unused; satisfies the parent signature.
+	 *
+	 * @return array<int, array<string, mixed>|object>
+	 */
 	public function get_data( array $ids_to_import = [] ): array {
 		return $this->rows;
 	}
diff --git a/tests/phpunit/test-db-scanners.php b/tests/phpunit/test-db-scanners.php
index 8bee1c43..fde1221b 100644
--- a/tests/phpunit/test-db-scanners.php
+++ b/tests/phpunit/test-db-scanners.php
@@ -10,8 +10,20 @@
 require_once __DIR__ . '/fakes/Fake_Hfcm_Importer.php';
 require_once __DIR__ . '/fakes/Fake_Ipcs_Importer.php';
 
+/**
+ * Tests for the Tier 2 DB-backed Unified Snippets scanners that adapt existing competitor
+ * importers (WPCode, HFCM, Insert PHP Code Snippet) through {@see DB_Scanner_Adapter}.
+ *
+ * Each test injects a {@see Fake_*_Importer} so the source plugin does not need to be installed.
+ *
+ * @group unified-snippets
+ */
 class DB_Scanners_Test extends TestCase {
 
+	/**
+	 * WPCode rows whose `code_type` is unsupported, or whose `code` is blank, are filtered
+	 * out so only importable snippets reach the scan results.
+	 */
 	public function test_wpcode_filters_unsupported_and_empty() {
 		$importer       = new Fake_Ihaf_Importer();
 		$importer->rows = [
@@ -56,6 +68,10 @@ public function test_wpcode_filters_unsupported_and_empty() {
 		$this->assertSame( 'php', $results[1]->type );
 	}
 
+	/**
+	 * HFCM's `status` column maps to `is_active`, and rows with an empty `snippet` are skipped
+	 * so they don't pollute the scan results.
+	 */
 	public function test_hfcm_active_flag_and_empty_skip() {
 		$importer       = new Fake_Hfcm_Importer();
 		$importer->rows = [
@@ -89,6 +105,11 @@ public function test_hfcm_active_flag_and_empty_skip() {
 		$this->assertFalse( $results[1]->is_active );
 	}
 
+	/**
+	 * Insert PHP Code Snippet rows map `status` (int) to `is_active`, fall back to a generated
+	 * "Insert PHP #N" name when `title` is empty, and inherit the scanner's elevated 'high' risk
+	 * level because the imported code executes PHP.
+	 */
 	public function test_ipcs_active_flag_name_fallback_and_risk() {
 		$importer       = new Fake_Ipcs_Importer();
 		$importer->rows = [
@@ -115,6 +136,10 @@ public function test_ipcs_active_flag_name_fallback_and_risk() {
 		$this->assertSame( 'Insert PHP #6', $results[1]->name );
 	}
 
+	/**
+	 * When the source plugin is not active, {@see DB_Scanner_Adapter::is_available()} returns
+	 * false and `scan()` short-circuits to an empty array without hitting the database.
+	 */
 	public function test_adapter_returns_empty_when_unavailable() {
 		if ( ! function_exists( 'is_plugin_active' ) ) {
 			require_once ABSPATH . 'wp-admin/includes/plugin.php';