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

With no annotations, the description carries the full burden and does so unusually well: it discloses the suspended state, the 200 {status: suspended} response shape, the no-charge behavior, the resume condition, the $0.025 USDC/x402 paywall and the historical audit note about the previously incorrect FREE documentation.

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 critical suspension/cost information is correctly front-loaded, but the body is bloated with internal audit references ('External audit 2026-07-30, BUG-2') and restated pricing history that add length without helping an agent select or call the tool.

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 suspended zero-output-schema tool the description is largely complete: status, cost, response shape, alternatives and resume behavior are all covered. The one real gap is the undocumented 'game' parameter, which leaves the only invocation input underspecified.

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 0% and the single 'game' parameter has no description or enum. The text partly compensates by implying the parameter is optional and filters to one of '25 supported card games,' but it never names valid values or the expected format, so an agent cannot construct the argument confidently.

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 names a specific deliverable: 'The DAY'S MARKET REPORT in one call, optionally for one game,' enumerating gainers/losers, volume leaders and a 25-game breakdown, and explicitly contrasts itself with trending_cards ('a summary of the whole market, not a ranked pick list'). The purpose is clear and sibling-differentiated, though it is buried beneath a dominant suspension notice that an agent will read first.

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?

It gives explicit when-to-use ('a user asks what happened in the card market today'), explicit alternatives with the condition that selects them (trending_cards for a ranked pick list; loan_terms_preview, sports_board, or the /jp/card/... page while suspended), and states the tool does not charge. Nothing is left to inference.

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