diff --git a/.pipeline/checkstyle.xml b/.pipeline/checkstyle.xml
index c32d131d..c1841cb5 100644
--- a/.pipeline/checkstyle.xml
+++ b/.pipeline/checkstyle.xml
@@ -47,7 +47,7 @@
 			<property name="severity" value="info"/>
 		</module>
 		<module name="JavadocMethod">
-			<property name="scope" value="protected"/>
+			<property name="accessModifiers" value="protected"/>
 			<property name="allowedAnnotations" value="Override"/>
 			<property name="severity" value="info"/>
 		</module>
diff --git a/foundation-models/openai/src/main/java/com/sap/ai/sdk/foundationmodels/openai/model/OpenAiChatMessage.java b/foundation-models/openai/src/main/java/com/sap/ai/sdk/foundationmodels/openai/model/OpenAiChatMessage.java
index 2bea24d0..181938c5 100644
--- a/foundation-models/openai/src/main/java/com/sap/ai/sdk/foundationmodels/openai/model/OpenAiChatMessage.java
+++ b/foundation-models/openai/src/main/java/com/sap/ai/sdk/foundationmodels/openai/model/OpenAiChatMessage.java
@@ -84,17 +84,36 @@ class OpenAiChatUserMessage implements OpenAiChatMessage {
     @Getter(onMethod_ = @Nullable)
     private final List<ContentPart> content = new ArrayList<>();
 
+    /**
+     * Add text to the user message.
+     *
+     * @param content The text content.
+     * @return The user message.
+     */
     @Nonnull
     public OpenAiChatUserMessage addText(@Nonnull final String content) {
       this.content.add(new ContentPartText().setText(content));
       return this;
     }
 
+    /**
+     * Add an image to the user message.
+     *
+     * @param content The image URL.
+     * @return The user message.
+     */
     @Nonnull
     public OpenAiChatUserMessage addImage(@Nonnull final String content) {
       return addImage(content, null);
     }
 
+    /**
+     * Add an image to the user message.
+     *
+     * @param content The image URL.
+     * @param detail The detail level of the image.
+     * @return The user message.
+     */
     @Nonnull
     public OpenAiChatUserMessage addImage(
         @Nonnull final String content, @Nullable final ImageDetailLevel detail) {
@@ -102,6 +121,12 @@ public OpenAiChatUserMessage addImage(
       return this;
     }
 
+    /**
+     * Add images or text to the user message.
+     *
+     * @param content The content(s) to add.
+     * @return The user message.
+     */
     @Nonnull
     public OpenAiChatUserMessage addContent(@Nonnull final ContentPart... content) {
       this.content.addAll(List.of(content));
@@ -147,11 +172,24 @@ public static class ContentPartImage implements ContentPart {
       @Nonnull
       private ImageUrl url;
 
+      /**
+       * Set the URL of the image.
+       *
+       * @param url The URL of the image.
+       * @return The image URL.
+       */
       @Nonnull
       public ContentPartImage setUrl(@Nonnull final String url) {
         return setUrl(url, null);
       }
 
+      /**
+       * Set the URL of the image.
+       *
+       * @param url The URL of the image.
+       * @param detailLevel The detail level of the image.
+       * @return The image URL.
+       */
       @Nonnull
       public ContentPartImage setUrl(
           @Nonnull final String url, @Nullable final ImageDetailLevel detailLevel) {
@@ -159,6 +197,7 @@ public ContentPartImage setUrl(
         return this;
       }
 
+      /** Image URL. */
       // { "url": "website.com/picture.jpg" }
       @JsonFormat(shape = Shape.OBJECT)
       @NoArgsConstructor
diff --git a/pom.xml b/pom.xml
index 84f607d8..aab51c71 100644
--- a/pom.xml
+++ b/pom.xml
@@ -35,7 +35,7 @@
     <assertj-core.version>3.25.3</assertj-core.version>
     <slf4j.version>2.0.16</slf4j.version>
     <spotless.version>2.43.0</spotless.version>
-    <checkstyle.version>8.41</checkstyle.version>
+    <checkstyle.version>10.17.0</checkstyle.version>
     <system-stubs.version>2.1.3</system-stubs.version>
     <surefire.version>3.2.2</surefire.version>
   </properties>