diff --git a/packages/oidc-signin-tool/src/certa/certaBackend.ts b/packages/oidc-signin-tool/src/certa/certaBackend.ts
index 7839ea59..196239c9 100644
--- a/packages/oidc-signin-tool/src/certa/certaBackend.ts
+++ b/packages/oidc-signin-tool/src/certa/certaBackend.ts
@@ -7,10 +7,11 @@ import * as fs from "fs";
 import * as path from "path";
 import type { AccessToken } from "@itwin/core-bentley";
 import { registerBackendCallback } from "@itwin/certa/lib/utils/CallbackUtils";
-import { ServiceAuthorizationClient, ServiceAuthorizationClientConfiguration } from "@itwin/service-authorization";
+import type { ServiceAuthorizationClientConfiguration } from "@itwin/service-authorization";
+import { ServiceAuthorizationClient } from "@itwin/service-authorization";
 import type { TestBrowserAuthorizationClientConfiguration, TestUserCredentials } from "../TestUsers";
 import { TestUtility } from "../TestUtility";
-import { getTokenCallbackName, getServiceAuthTokenCallbackName } from "./certaCommon";
+import { getServiceAuthTokenCallbackName, getTokenCallbackName } from "./certaCommon";
 
 // A backend to use within Certa's `backendInitModule` to setup OIDC sign-in.
 
@@ -57,7 +58,6 @@ async function signin(user: TestUserCredentials, oidcConfig?: TestBrowserAuthori
   if (undefined === token)
     throw new Error("Failed to get access token");
 
-
   return token;
 }
 
@@ -78,7 +78,6 @@ registerBackendCallback(
   },
 );
 
-
 registerBackendCallback(getServiceAuthTokenCallbackName, async (oidcConfig: ServiceAuthorizationClientConfiguration): Promise<string> => {
   return signinWithServiceAuthClient(oidcConfig);
-});
\ No newline at end of file
+});
diff --git a/packages/oidc-signin-tool/src/certa/certaCommon.ts b/packages/oidc-signin-tool/src/certa/certaCommon.ts
index c11eb209..e4adc66b 100644
--- a/packages/oidc-signin-tool/src/certa/certaCommon.ts
+++ b/packages/oidc-signin-tool/src/certa/certaCommon.ts
@@ -18,8 +18,10 @@ export async function getAccessTokenFromBackend(user: TestUserCredentials, oidcC
   return accessToken;
 }
 
-
+/**
+ * Retrieves a service authorization token from the backend.
+ */
 export async function getServiceAuthTokenFromBackend(oidcConfig: ServiceAuthorizationClientConfiguration): Promise<string> {
   const accessToken = await executeBackendCallback(getServiceAuthTokenCallbackName, oidcConfig);
   return accessToken;
-}
\ No newline at end of file
+}