diff --git a/src/Documentation/DocumentationMenuItem.php b/src/Documentation/DocumentationMenuItem.php
index 3e28aea48..99575a0fc 100644
--- a/src/Documentation/DocumentationMenuItem.php
+++ b/src/Documentation/DocumentationMenuItem.php
@@ -10,7 +10,10 @@
 final readonly class DocumentationMenuItem
 {
     /**
-     * @param non-empty-string|null $slug
+     * @param string $href The URL path for the documentation menu item. Must be a non-empty string starting with '/', 'http://', or 'https://'
+     * @param string $label The display text for the menu item. Must be a non-empty string
+     * @param non-empty-string|null $slug The unique identifier for the documentation file. If null, indicates a menu item without content
+     * @param bool $isNew Whether this menu item represents new documentation
      */
     public function __construct(
         private string $href,
@@ -18,6 +21,12 @@ public function __construct(
         private ?string $slug,
         private bool $isNew = false,
     ) {
+        Assert::notEmpty($href, 'Documentation href cannot be empty');
+        Assert::true(
+            str_starts_with($href, '/') || str_starts_with($href, 'http://') || str_starts_with($href, 'https://'),
+            'Documentation href must start with a forward slash, http://, or https://'
+        );
+        Assert::notEmpty($label, 'Documentation label cannot be empty');
     }
 
     public function getHref(): string
@@ -43,12 +52,41 @@ public function getSlug(): ?string
         return $this->slug;
     }
 
+    /**
+     * Checks if the documentation file exists for this menu item.
+     * Throws an exception if the file does not exist when a slug is provided.
+     * 
+     * @return bool True if the documentation file exists, false if slug is null
+     * @throws \Webmozart\Assert\InvalidArgumentException If the file does not exist when slug is provided
+     */
+    public function hasDocumentation(): bool
+    {
+        if ($this->slug === null) {
+            return false;
+        }
+
+        $documentationFilePath = $this->getDocumentationFilePath();
+        Assert::fileExists($documentationFilePath, sprintf('Documentation file must exist at "%s"', $documentationFilePath));
+        
+        return true;
+    }
+
     public function getMarkdownContents(): string
     {
         Assert::notNull($this->slug);
-        $documentationFilePath = __DIR__ . '/../../resources/docs/' . $this->slug . '.md';
+        $documentationFilePath = $this->getDocumentationFilePath();
 
         Assert::fileExists($documentationFilePath);
         return FileSystem::read($documentationFilePath);
     }
+
+    /**
+     * Gets the full path to the documentation file.
+     * 
+     * @return string The absolute path to the documentation file
+     */
+    private function getDocumentationFilePath(): string
+    {
+        return __DIR__ . '/../../resources/docs/' . $this->slug . '.md';
+    }
 }
diff --git a/src/ValueObject/AppliedRule.php b/src/ValueObject/AppliedRule.php
index 5e341d098..7481d60ef 100644
--- a/src/ValueObject/AppliedRule.php
+++ b/src/ValueObject/AppliedRule.php
@@ -6,9 +6,20 @@
 
 use App\Exception\ShouldNotHappenException;
 use Nette\Utils\Strings;
+use Webmozart\Assert\Assert;
 
 final readonly class AppliedRule
 {
+    private const EXPECTED_CLASS_PARTS_COUNT_MIN = 5;
+    private const EXPECTED_CLASS_PARTS_COUNT_MAX = 6;
+    private const CATEGORY_INDEX = 1;
+    private const RECTOR_LITERAL_INDEX_5_PARTS = 2;
+    private const RECTOR_LITERAL_INDEX_6_PARTS = 3;
+    private const NODE_CLASS_INDEX_5_PARTS = 3;
+    private const NODE_CLASS_INDEX_6_PARTS = 4;
+    private const SHORT_CLASS_INDEX_5_PARTS = 4;
+    private const SHORT_CLASS_INDEX_6_PARTS = 5;
+
     private string $shortRectorClass;
 
     public function __construct(
@@ -40,16 +51,68 @@ public function getTestFixtureNamespace(): string
     public function getTestFixtureDirectoryPath(): string
     {
         $classParts = explode('\\', $this->rectorClass);
+        $partsCount = count($classParts);
+        
+        // Validate class structure - allow 5 or 6 parts (6 parts when version number is present)
+        Assert::true(
+            $partsCount >= self::EXPECTED_CLASS_PARTS_COUNT_MIN && $partsCount <= self::EXPECTED_CLASS_PARTS_COUNT_MAX,
+            sprintf(
+                'Rector class "%s" must have %d or %d parts (e.g. "Rector\\Category\\Rector\\Node\\SomeRector" or "Rector\\Category\\Version\\Rector\\Node\\SomeRector")',
+                $this->rectorClass,
+                self::EXPECTED_CLASS_PARTS_COUNT_MIN,
+                self::EXPECTED_CLASS_PARTS_COUNT_MAX
+            )
+        );
 
-        $category = $classParts[1];
-        $rulesDirectory = 'rules-tests/' . $category;
+        // Validate first part is "Rector"
+        Assert::same($classParts[0], 'Rector', sprintf('Rector class "%s" must start with "Rector"', $this->rectorClass));
+
+        // Determine if we have a version part (6 parts) or not (5 parts)
+        $hasVersion = $partsCount === self::EXPECTED_CLASS_PARTS_COUNT_MAX;
+        
+        // Validate "Rector" literal is at the correct position
+        $rectorLiteralIndex = $hasVersion ? self::RECTOR_LITERAL_INDEX_6_PARTS : self::RECTOR_LITERAL_INDEX_5_PARTS;
+        Assert::same(
+            $classParts[$rectorLiteralIndex],
+            'Rector',
+            sprintf('Rector class "%s" must have "Rector" at index %d', $this->rectorClass, $rectorLiteralIndex)
+        );
 
-        $nodeClass = $classParts[3];
-        $shortClass = $classParts[4];
+        // Get required parts with correct indices
+        // When there's a version (6 parts), use the version as the category; otherwise use the base category
+        $categoryIndex = $hasVersion ? 2 : self::CATEGORY_INDEX;
+        $category = $this->getClassPart($classParts, $categoryIndex, 'category');
+        $nodeClassIndex = $hasVersion ? self::NODE_CLASS_INDEX_6_PARTS : self::NODE_CLASS_INDEX_5_PARTS;
+        $shortClassIndex = $hasVersion ? self::SHORT_CLASS_INDEX_6_PARTS : self::SHORT_CLASS_INDEX_5_PARTS;
+        
+        $nodeClass = $this->getClassPart($classParts, $nodeClassIndex, 'node class');
+        $shortClass = $this->getClassPart($classParts, $shortClassIndex, 'short class');
+
+        $rulesDirectory = 'rules-tests/' . $category;
 
         return $rulesDirectory . '/Rector/' . $nodeClass . '/' . $shortClass . '/Fixture';
     }
 
+    /**
+     * @param string[] $classParts
+     */
+    private function getClassPart(array $classParts, int $index, string $partName): string
+    {
+        Assert::keyExists(
+            $classParts,
+            $index,
+            sprintf('Missing %s in rector class "%s"', $partName, $this->rectorClass)
+        );
+
+        $part = $classParts[$index];
+        Assert::notEmpty(
+            $part,
+            sprintf('Empty %s in rector class "%s"', $partName, $this->rectorClass)
+        );
+
+        return $part;
+    }
+
     /**
      * Mimics @see \App\RuleFilter\ValueObject\RuleMetadata::getSlug()
      */