Silent Pagination Truncation when using `--page-size` or `--starting-token` on affected services

[Abuhaithem]

Describe the bug

There is a silent data truncation bug in the AWS CLI's automatic pagination logic. When users run a paginated command that happens to have a native API limit_key named "PageSize" (e.g., aws elbv2 describe-load-balancers), explicitly using the global --page-size argument will silently disable automatic pagination. The CLI will fetch only the first page and exit with a 0 exit code, giving the user the false impression that they have fetched all resources in batches.

Similarly, if an API's input_token is exactly "StartingToken" (e.g., aws ssm-quicksetup list-configurations), using the global --starting-token argument will also silently disable automatic pagination.

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

When using the global --page-size flag, the CLI should automatically fetch all items across all pages in batches of the specified size. It should not stop after the first page unless --no-paginate or --max-items is specified.

Current Behavior

When providing --page-size to an operation whose underlying API natively uses PageSize as its pagination limit parameter, the AWS CLI mistakenly identifies the global argument as a manual, undocumented API parameter and disables automatic pagination. It retrieves exactly one page (of size equal to --page-size) and exits with code 0.

There are no errors, uncaught exceptions, or stack traces—it fails silently.

Reproduction Steps

Observe the difference in results when using --page-size:

# This fetches ALL load balancers automatically via pagination.
aws elbv2 describe-load-balancers 

# EXPECTED: Fetches ALL load balancers automatically, but in batches of 1.
# ACTUAL: Fetches EXACTLY 1 load balancer, silently disables pagination, and exits with code 0!
aws elbv2 describe-load-balancers --page-size 1

Possible Solution

The issue is caused by a typographical error and a missing list element in awscli/customizations/paginate.py within the check_should_enable_pagination function:

    normalized_paging_args = ['start_token', 'max_items']

1. Typo: start_token is used instead of the correct starting_token.
2. Omission: page_size is completely missing from normalized_paging_args.

Fix the tuple to include both correctly, matching the paging_params list defined slightly lower in the same file:

-    normalized_paging_args = ['start_token', 'max_items']
+    normalized_paging_args = ['starting_token', 'page_size', 'max_items']

Additional Information/Context

The following API operations are affected and will suffer from silent truncation when --page-size is provided:

• ce (Cost Explorer): GetReservationPurchaseRecommendation, GetRightsizingRecommendation, ListCommitmentPurchaseAnalyses, ListSavingsPlansPurchaseRecommendationGeneration
• elb / elbv2: DescribeLoadBalancers, DescribeAccountLimits, DescribeTargetGroups, DescribeListeners, DescribeRules, DescribeSSLPolicies, DescribeTrustStores, etc.
• lakeformation: GetWorkUnits
• mailmanager: ListAddonInstances, ListArchives, ListRuleSets, ListTrafficPolicies, etc.
• pinpoint-email: GetDedicatedIps, ListConfigurationSets, ListEmailIdentities, etc.
• servicecatalog: SearchProductsAsAdmin, ListPortfolios, ListProvisionedProductPlans, ScanProvisionedProducts, etc.
• sesv2: ListMultiRegionEndpoints, ListTenants, etc.
• ssm-quicksetup: ListConfigurations and ListConfigurationManagers (affected by --starting-token truncation).

This bug is particularly insidious for users operating large environments who explicitly use --page-size to prevent timeouts when retrieving thousands of ELBs or resources.

CLI version used

aws-cli/1.x.x and aws-cli/2.x.x (Affects all recent v1 and v2 versions since the pagination customization was originally implemented)

Environment details (OS name and version, etc.)

All environments and operating systems (Linux, macOS, Windows)