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

Annotations already establish this as a safe, read-only, idempotent operation. The description adds useful behavioral detail beyond that: it searches a large multi-game database, returns real sold-listing based prices in USD for ungraded and PSA 10 states, and outputs card ids for other tools. It does not mention pagination or result limits, but the schema and output schema cover those aspects.

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 three tightly packed sentences with no filler: primary use case, search scope and return values, then explicit non-uses. The critical routing instruction is front-loaded, so an agent learns its purpose and boundaries immediately.

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 search tool with an output schema and safe read-only annotations, this description is complete: it covers scope, supported categories, output semantics, downstream consumers, and exclusion cases. An agent can correctly select and invoke the tool without needing additional context.

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 75%, with query and set_id already documented, and the description's phrase 'by name, set, number and year' largely echoes the query parameter examples. It adds no meaningful guidance for game, limit, or set_id beyond what the schema provides, so the baseline 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 states a specific verb ('Searches') and resource ('1.5M+ Pokémon, Magic, Yu-Gi-Oh!, One Piece, Lorcana, sports and entertainment cards'), and clearly distinguishes this tool from siblings by saying to use it first when a user names a card and wants its value, price, or grading advice. It also says what it returns (ungraded and PSA 10 prices, card ids) and what it is not for.

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 gives explicit when-to-use guidance ('Use this first when the user names a trading card and wants its value, price, or whether to grade it') and explicit exclusions ('Do not use for sealed product, for cards you already have an id for, or for price prediction'). It also names downstream tools that consume its returned card ids, which helps an agent choose the right sequence.

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