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

Goes well beyond the annotations (readOnly/openWorld/non-idempotent/non-destructive) by disclosing the cost model: 'One admitted API call consumes one shared account request, including admitted errors' and 'No automatic retries.' The quota/consumption detail and the no-retry warning are exactly the operational facts an agent needs before calling, and nothing contradicts the declared hints.

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?

Purpose, return shape, parameter guidance, workflow ordering and quota caveat are all packed into five dense, front-loaded sentences with no filler. Each sentence carries decision-relevant information for the agent.

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 values need not be spelled out, yet the description still summarizes them (stable tcg_ IDs, identifying fields, pricing availability, next_cursor). Combined with annotations and the quota note this is nearly complete; the only minor gap is that none of the non-required filter params (game/set/query/limit) are elaborated.

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?

With only 50% schema coverage, the description compensates by explaining view=full ('compare printed_number and finish_details') and the cursor lifecycle ('returns ... next_cursor', 'Stop when next_cursor is null' via the schema). It adds real meaning for view and pagination, though game/set/query/limit are left entirely to the schema.

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 (Find) and resource (variant candidates/card variants) and scopes it to six games, immediately signalling it is a lookup/browse tool rather than a pricing tool. It differentiates from pricing siblings implicitly ('even without a current price', 'before requesting prices') but never names a sibling like search_catalogue_cards directly, so an agent must infer the boundary.

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?

Provides clear workflow context: use view=full to compare printed_number and finish_details, preserve separate printings, and choose an exact candidate before requesting prices. This tells the agent where this tool fits relative to the price tools, but it does not name an explicit alternative or state when-not to use this tool.

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