diff --git a/src/server/api/endpoints/charts/drive.ts b/src/server/api/endpoints/charts/drive.ts
index f090a7f5f1..c17a9413cd 100644
--- a/src/server/api/endpoints/charts/drive.ts
+++ b/src/server/api/endpoints/charts/drive.ts
@@ -10,7 +10,7 @@ export const meta = {
 	params: {
 		span: $.str.or(['day', 'hour']).note({
 			desc: {
-				'ja-JP': '集計のスパン'
+				'ja-JP': '集計のスパン (day または hour)'
 			}
 		}),
 
diff --git a/src/server/api/endpoints/charts/network.ts b/src/server/api/endpoints/charts/network.ts
index 07ba19d5e0..49d87bfc22 100644
--- a/src/server/api/endpoints/charts/network.ts
+++ b/src/server/api/endpoints/charts/network.ts
@@ -10,7 +10,7 @@ export const meta = {
 	params: {
 		span: $.str.or(['day', 'hour']).note({
 			desc: {
-				'ja-JP': '集計のスパン'
+				'ja-JP': '集計のスパン (day または hour)'
 			}
 		}),
 
diff --git a/src/server/api/endpoints/charts/notes.ts b/src/server/api/endpoints/charts/notes.ts
index 06ed3b7d41..a9dc068260 100644
--- a/src/server/api/endpoints/charts/notes.ts
+++ b/src/server/api/endpoints/charts/notes.ts
@@ -10,7 +10,7 @@ export const meta = {
 	params: {
 		span: $.str.or(['day', 'hour']).note({
 			desc: {
-				'ja-JP': '集計のスパン'
+				'ja-JP': '集計のスパン (day または hour)'
 			}
 		}),
 
diff --git a/src/server/api/endpoints/charts/users.ts b/src/server/api/endpoints/charts/users.ts
index 1dea4d5c4d..78d35fb645 100644
--- a/src/server/api/endpoints/charts/users.ts
+++ b/src/server/api/endpoints/charts/users.ts
@@ -10,7 +10,7 @@ export const meta = {
 	params: {
 		span: $.str.or(['day', 'hour']).note({
 			desc: {
-				'ja-JP': '集計のスパン'
+				'ja-JP': '集計のスパン (day または hour)'
 			}
 		}),