cards_skins

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

With no annotations, the description carries the burden, and it does so well by disclosing that responses are cached for 24 hours, provenance includes the route and original fetch time, and rows are returned unchanged with no computed fields. It also gives concrete response-shape details such as a bare array and field names, which is meaningful behavioral context beyond a generic list description.

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 front-loaded with the core purpose and then adds supporting behavioral details. The byte count and 'measured public response' phrasing are slightly more specific than necessary, but no sentence is filler and the structure is logical.

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, no-output-schema metadata tool, the description is complete: it states the source route, the response shape and fields, caching behavior, provenance reporting, and what the tool does not do. Nothing essential for selecting or invoking this tool 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 baseline is 4. The description compensates further by documenting the exact fields returned, which is the only semantic information an agent would need for this no-input tool.

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: 'List the skin rows returned by GET /cards/skins.' It further clarifies scope by naming the exact fields in each row and explicitly noting that no BCX, donor, or account-attribution field is present, which helps distinguish it from player- or account-level tools.

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?

Usage context is implied rather than explicit: it is a raw metadata list, and the statement that it 'does not calculate availability or prices' signals when not to use it. However, it does not name alternatives or state a concrete condition for choosing this tool over siblings such as player_skins or cards_find.

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