diff --git a/src/scalar.rs b/src/scalar.rs
index 81abc89..76aa7e1 100644
--- a/src/scalar.rs
+++ b/src/scalar.rs
@@ -16,6 +16,9 @@ pub type Id = uuid::Uuid;
 pub struct Ulid(pub UlidPrimitive);
 
 #[Scalar]
+/// The ULID scalar type represents a Universally Unique Lexicographically Sortable Identifier as defined by the ULID specification.
+/// ULIDs are 26-character strings that are URL-safe, case-insensitive, and lexicographically sortable,
+/// making them ideal for distributed systems requiring time-ordered unique identifiers.
 impl ScalarType for Ulid {
     fn parse(value: Value) -> InputValueResult<Self> {
         match value {