diff --git a/packages/techdocs-common/src/stages/publish/types.ts b/packages/techdocs-common/src/stages/publish/types.ts
index 7d0644ce7c..83fee55133 100644
--- a/packages/techdocs-common/src/stages/publish/types.ts
+++ b/packages/techdocs-common/src/stages/publish/types.ts
@@ -39,6 +39,7 @@ export type PublishResponse = {
 
 /**
  * Type to hold metadata found in techdocs_metadata.json and associated with each site
+ * @param etag ETag of the resource used to generate the site. Usually the latest commit sha of the source repository.
  */
 export type TechDocsMetadata = {
   site_name: string;