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

Annotations readOnlyHint=true and idempotentHint=true already tell the agent the call is read-only and idempotent. Beyond that, the description discloses the paid nature, the single-voucher/settlement flow, and the signed XDR-1 receipt for the entire batch, which is genuinely useful behavioral context not present in the structured fields.

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 sentences carry the core capability, pricing, and billing behavior without fluff. The enumeration of 17 check types is a bit long but serves as a quick inventory for the agent; however, this list partially duplicates the schema enum and could be trimmed.

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 one parameter, a rich schema, and an output schema present, the description covers the essential operational details: max count, cost model, and per-batch receipt. It does not explain partial-failure behavior, but the output schema likely covers per-item results, so nothing critical seems 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?

The input schema has full description coverage for the only parameter, items, including the {tool, value} shape and max/min bounds. The description enumerates the acceptable check types, but these are already in the schema enum, and it adds no new parametric meaning beyond what the schema provides, so the baseline 3 applies.

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 description opens with a specific verb and resource: 'Run up to 50 identifier checks in ONE paid call,' so the agent immediately knows it is a batch execution tool. It also distinguishes itself from the many single-check sibling tools by emphasizing the batch scope and the one-payment model.

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 makes the batch-vs-single tradeoff explicit with 'one voucher, one settlement' and 'at 50 items, 10x cheaper per check than single calls,' which tells an agent this is the cost-efficient route for multiple validations. It does not explicitly state when to choose a single-check sibling instead, but the context strongly implies that for one check you would not use a batch tool.

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