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

Annotations already establish readOnly/openWorld/non-destructive, but the description adds substantive operational context: one admitted call (including errors) consumes one shared account request, and there are no automatic retries. It does not explain why the operation is non-idempotent, but its quota and retry disclosure clearly exceeds the 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?

Four sentences, purpose front-loaded, and each sentence carries distinct information (stored vs fresh, sibling routing, quota cost, no retries). Reasonably tight, though the quota and retry sentences could be merged.

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?

An output schema exists, so return-value detail is not required, yet the description still notes game fields and image paths. Combined with the quota/retry disclosure and the sibling pointer, an agent has enough to call this correctly; only the view parameter remains unexplained.

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 coverage is only 50%: card_id is richly documented in the schema, but the view enum (compact/full) is undocumented in both the schema and the description. 'Includes game fields and image paths' gestures at returned content but never ties it to the compact/full choice, leaving the description unable to compensate for the gap.

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 verb (read) and resource (stored variant metadata + pricing availability), and distinguishes itself from get_card_image by naming that sibling. It does not, however, draw a clear line against get_card_prices or get_catalogue_card, which also concern card data.

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?

'without requiring a fresh quote' signals when to prefer this stored-data read over a live price fetch, and it explicitly routes artwork requests to get_card_image. No explicit exclusions or coverage of the other pricing siblings, so it falls short of a 5.

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