diff --git a/src/lib/components/AddToolServerModal.svelte b/src/lib/components/AddToolServerModal.svelte
index d146aeca0..74571c308 100644
--- a/src/lib/components/AddToolServerModal.svelte
+++ b/src/lib/components/AddToolServerModal.svelte
@@ -78,21 +78,20 @@
 			return;
 		}
 
+		if (auth_type === 'oauth_2.1_static' && (!oauthClientId || !oauthClientSecret)) {
+			toast.error($i18n.t('Please enter Client ID and Client Secret'));
+			return;
+		}
+
+		// client_id is the tool server ID (used as the internal lookup key for both flows).
+		// For static, client_secret signals the backend to use the static credential path.
+		// The actual OAuth client_id/secret come from the connection info at save time.
 		const formData: { url: string; client_id: string; client_secret?: string } = {
 			url: url,
-			client_id: id
+			client_id: id,
+			...(auth_type === 'oauth_2.1_static' ? { client_secret: oauthClientSecret } : {})
 		};
 
-		// For static OAuth, include client credentials
-		if (auth_type === 'oauth_2.1_static') {
-			if (!oauthClientId || !oauthClientSecret) {
-				toast.error($i18n.t('Please enter Client ID and Client Secret'));
-				return;
-			}
-			formData.client_id = id;
-			formData.client_secret = oauthClientSecret;
-		}
-
 		const res = await registerOAuthClient(localStorage.token, formData, 'mcp').catch((err) => {
 			toast.error($i18n.t('Registration failed'));
 			return null;