diff --git a/astro.config.mjs b/astro.config.mjs
index a233d31..f0abda8 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -77,6 +77,7 @@ function transformSiteStructureToSidebar(siteStructure) {
   if (siteStructure.tooling.linterRules?.length > 0) {
     toolingItems.push({
       label: "Protobuf Linter",
+      collapsed: true,
       items: [
         "tooling/linter",
         {
@@ -94,6 +95,7 @@ function transformSiteStructureToSidebar(siteStructure) {
   if (siteStructure.tooling.openAPILinterRules?.length > 0) {
     toolingItems.push({
       label: "OpenAPI Linter",
+      collapsed: true,
       items: [
         "tooling/openapi-linter",
         {
diff --git a/src/utils/sidebar-from-site-structure.ts b/src/utils/sidebar-from-site-structure.ts
index 37372e4..31d3de0 100644
--- a/src/utils/sidebar-from-site-structure.ts
+++ b/src/utils/sidebar-from-site-structure.ts
@@ -111,6 +111,7 @@ function assembleToolingItems(siteStructure: SiteStructure): any[] {
   ) {
     items.push({
       label: "Protobuf Linter",
+      collapsed: true,
       items: [
         "tooling/linter",
         {
@@ -131,6 +132,7 @@ function assembleToolingItems(siteStructure: SiteStructure): any[] {
   ) {
     items.push({
       label: "OpenAPI Linter",
+      collapsed: true,
       items: [
         "tooling/openapi-linter",
         {