diff --git a/crates/tombi-comment-directive/src/root.rs b/crates/tombi-comment-directive/src/root.rs
index e26c6f8e..d954c64d 100644
--- a/crates/tombi-comment-directive/src/root.rs
+++ b/crates/tombi-comment-directive/src/root.rs
@@ -4,6 +4,10 @@ use tombi_toml_version::TomlVersion;
 #[serde(deny_unknown_fields)]
 #[serde(rename_all = "kebab-case")]
 #[cfg_attr(feature = "jsonschema", derive(schemars::JsonSchema))]
+#[cfg_attr(feature = "jsonschema", schemars(extend("$id" = "tombi://json.tombi.dev/root-comment-directive.json")))]
 pub struct RootCommentDirective {
+    /// # TOML version.
+    ///
+    /// This directive specifies the TOML version of this document, with the highest priority.
     pub toml_version: Option<TomlVersion>,
 }
diff --git a/json.tombi.dev/api/json/catalog.json b/json.tombi.dev/api/json/catalog.json
index 8852056f..3c8ff348 100644
--- a/json.tombi.dev/api/json/catalog.json
+++ b/json.tombi.dev/api/json/catalog.json
@@ -1,5 +1,6 @@
 {
-  "$schema": "tombi://json.tombi.dev/api/json/catalog.json",
+  "$id": "tombi://json.tombi.dev/api/json/catalog.json",
+  "$schema": "http://json-schema.org/draft-07/schema#",
   "version": 1,
   "schemas": [
     {
diff --git a/json.tombi.dev/root-comment-directive.json b/json.tombi.dev/root-comment-directive.json
index 9fcad0b0..48e8f4cb 100644
--- a/json.tombi.dev/root-comment-directive.json
+++ b/json.tombi.dev/root-comment-directive.json
@@ -1,9 +1,12 @@
 {
-  "$schema": "tombi://json.tombi.dev/root-comment-directive.json",
+  "$id": "tombi://json.tombi.dev/root-comment-directive.json",
+  "$schema": "http://json-schema.org/draft-07/schema#",
   "title": "RootCommentDirective",
   "type": "object",
   "properties": {
     "toml-version": {
+      "title": "TOML version.",
+      "description": "This directive specifies the TOML version of this document, with the highest priority.",
       "anyOf": [
         {
           "$ref": "#/definitions/TomlVersion"
@@ -19,7 +22,10 @@
     "TomlVersion": {
       "title": "TOML version.",
       "type": "string",
-      "enum": ["v1.0.0", "v1.1.0-preview"]
+      "enum": [
+        "v1.0.0",
+        "v1.1.0-preview"
+      ]
     }
   }
 }
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 1b20557a..f00afab3 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,5 +1,3 @@
-# tombi: toml-version = "v1.0.0"
-
 [toolchain]
 channel = "stable"
 components = ["clippy", "rust-analyzer", "rustfmt"]