purchase_stats

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

With no annotations provided, the description fully discloses behaviors: it makes no purchase, performs one logical GET without auto-fetching continuation pages, imposes a 100-row/256 KiB array limit with reported truncation, and refuses oversized records without partial fields. Filtering effectiveness is also disclosed. This exceeds typical transparency expectations.

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 description is moderately long (~130 words) but every sentence adds critical operational detail. It is well-structured, front-loaded with the primary purpose, and avoids redundancy. The additional caveats about pagination, limits, and filtering are all necessary for correct invocation.

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 zero-parameter read-only statistics tool with no output schema, the description is remarkably complete. It covers scope, safety, pagination behavior, response size limits, filtering semantics, and data retention. No essential information for calling the tool correctly is 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 tool has zero parameters, so the schema coverage is trivially 100%. Per guidelines, a baseline of 4 is appropriate when there are no parameters. The description adds meta-information about required inputs being policy-driven but does not need to explain specific parameters since none exist.

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 states a clear verb ('Read') and specific resource ('public pack and promotional-card statistics'), distinguishing it from the many sibling tools by its domain focus. It also clarifies that it concerns statistics, not purchases, removing ambiguity from the name.

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 implies when to use it (when you need public pack or promotional-card statistics) and explicitly notes that it makes no purchase, but it does not name alternative tools or provide explicit exclusions. The guidance is adequate for a tool with zero parameters but lacks direct sibling differentiation.

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