list_billing_transfer_end_customers

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already provide readOnlyHint true, destructiveHint false, and openWorldHint true, so the safety profile is known. The description adds caller scope and the DPMA/PMA relationship, but the opening 'Manage' wording is ambiguous and could imply mutating mappings. This is not a hard contradiction because the operation is explicitly described as 'Lists', but it does not enrich behavioral transparency much beyond existing annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The core definition is relatively short, but the first sentence is overly broad and not needed for this tool's actual purpose. The description could be improved by removing the 'Manage... and list program management accounts' fragment and leading with the concrete listing statement.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With five parameters, no output schema, and a closely related sibling tool bank, the description should clarify what an end-customer mapping looks like, how records are scoped, and whether pagination or special headers affect results. It provides only who can call and the main identifiers, leaving important operational context missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 20%, and the description merely names `dpmaId` and `resellerPmaAccountId` as identifiers without explaining their meaning or format. It does not compensate for the lack of schema descriptions for `includeRevoked`, `X-Tenant-Id`, or the full `customerContext` semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The core statement that the tool 'Lists the end-customer AWS account mappings under a reseller's program management account' is clear and specific, with the two key identifiers named. It loses the top score because the opening sentence describes a broader 'Manage' role and 'list program management accounts,' which is closer to sibling tools and could confuse an agent.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives authorization context—who may call the tool—but does not explain when to choose this over the very similar sibling `list_billing_transfer_end_customers_by_reseller` or `list_billing_transfer_reseller_accounts`. There is no when-to-use guidance or exclusion of alternative tools.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.