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

Annotations already declare readOnly, idempotent, non-destructive, openWorld, so the safety profile is covered. The description adds the endpoint path and the per-customer scoping constraint, but says nothing about ordering, volume, or pagination behavior beyond what the schema's page field states.

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?

Two short fragments with zero waste, front-loading the resource scope. It is arguably too terse for a tool with a same-resource sibling, but nothing is redundant.

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?

For a simple two-parameter read tool with full schema coverage and complete annotations, the essentials are present. The notable gap is sibling routing against pinpayments_list_charges and pinpayments_search_charges, which an agent must infer.

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 100%, so both customer_token and page (including the 25-per-page and next_page guidance) are fully documented in the schema. The description adds no parameter meaning beyond echoing the customer token in the path. Baseline 3 is appropriate.

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?

States a specific resource (charges) with a scope qualifier (made by one customer) and reinforces it with the exact REST endpoint. It is distinguishable from pinpayments_list_charges, though the differentiation is implicit rather than spelled out.

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 per-customer scoping implies you should use this when you have a customer token rather than searching all charges, but no alternative (pinpayments_list_charges, pinpayments_search_charges) is named and no when-not condition is given.

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