chore: add comments

Author: durran

src/cmap/auth/mongo_credentials.ts

@@ -69,7 +69,32 @@ export interface AuthMechanismProperties extends Document {
   ALLOWED_HOSTS?: string[];
   /** The resource token for OIDC auth in Azure and GCP. */
   TOKEN_RESOURCE?: string;
-  /** A custom AWS credential provider to use. */
+  /**
+   * A custom AWS credential provider to use. An example using the AWS SDK default provider chain:
+   *
+   * ```ts
+   * const client = new MongoClient(process.env.MONGODB_URI, {
+   *   authMechanismProperties: {
+   *     AWS_CREDENTIAL_PROVIDER: fromNodeProviderChain()
+   *   }
+   * });
+   * ```
+   *
+   * Using a custom function that returns AWS credentials:
+   *
+   * ```ts
+   * const client = new MongoClient(process.env.MONGODB_URI, {
+   *   authMechanismProperties: {
+   *     AWS_CREDENTIAL_PROVIDER: async () => {
+   *       return {
+   *         accessKeyId: process.env.ACCESS_KEY_ID,
+   *         secretAccessKey: process.env.SECRET_ACCESS_KEY
+   *       }
+   *     }
+   *   }
+   * });
+   * ```
+   */
   AWS_CREDENTIAL_PROVIDER?: AWSCredentialProvider;
 }