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

The annotations already mark this as read-only and non-destructive, and the description adds valuable behavioral context beyond that: the 50% gem-rate calculation, expected net profit formula, the requirement for both PSA 9 and PSA 10 prices, and the consequent exclusion of thin-market outliers.

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?

Three sentences, each earning its place: the use case is front-loaded, the second sentence gives the core calculation and eligibility rule, and the third states the output routing and an important exclusion. No redundant wording.

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 ranking tool with an output schema and safety-carrying annotations, the description provides everything an agent needs: the user intent trigger, the exact business logic, the data prerequisites, the output target, and a clear when-not-to-use boundary.

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 schema already documents game, set_slug, and grading_fee_usd, and the description reinforces the roles of game/sport/set and the fee in the calculation. However, the limit parameter has no schema description and the tool description does not clarify it either, so coverage is good but not complete.

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 action (rank priced cards by grading payoff), a clear resource (cards in a game, sport, or set), and a distinctive output (card ids for grading_roi). It also explicitly excludes single-card lookups, which helps separate it from sibling 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?

It explicitly says when to use the tool ('Use this when the user asks which cards...') and gives an exclusion ('Do not use for a single named card'). However, it does not name an alternative tool for the excluded case, so it stops short of full alternative guidance.

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