diff --git a/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/StructuredParameter.java b/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/StructuredParameter.java
index 0b4a36e..fa326d5 100644
--- a/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/StructuredParameter.java
+++ b/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/StructuredParameter.java
@@ -2,6 +2,31 @@
 
 import javax.json.JsonObjectBuilder;
 
+/**
+ * A structured parameter usable as logging payload.
+ *
+ * <p>Any instance of {@link StructuredParameter} can be passed as a log parameter to the {@code *f}
+ * family of logging functions on {@link org.jboss.logging.Logger}.
+ *
+ * <p>Example:
+ *
+ * <pre>{@code
+ * StructuredParameter p1 = ...;
+ * StructuredParameter p2 = ...;
+ *
+ * logger.logf("Something interesting happened.", p1, p2);
+ * }</pre>
+ *
+ * @see KeyValueParameter
+ * @see Label
+ */
 public interface StructuredParameter {
+
+  /**
+   * The JSON to be embedded in the log entry.
+   *
+   * <p>May contain multiple keys and values as well as nested objects. Each top-level entry of the
+   * returned object is embedded as a top-level entry in the log entry.
+   */
   JsonObjectBuilder json();
 }