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

With no annotations, the description carries the full behavioral burden, and it does disclose a lot about what comes back: medians for ungraded and each grader, sale counts, window, low/high, newest sale, population totals, card page, buy link, and a live eBay copy when one exists. However, it says nothing about authentication needs, rate limits, cost, or what happens on a bad or ambiguous card identifier. The output-content detail is strong but operational behavior is absent.

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?

It is a single very long run-on sentence with a comma-spliced list of a dozen return fields. The key idea is front-loaded, which helps, but the enumeration of graders and fields is dense and could be trimmed or split. Nothing is truly wasted, yet the structure makes it harder to scan than necessary.

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?

No output schema exists, so the description must describe returns, and it does so thoroughly, covering grade coverage, statistics, population, links, and the optional eBay copy. What remains missing is usage/routing context against four closely related siblings and any error or ambiguity behavior for the name-based lookup.

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 100% and the single `card` parameter is richly documented in the schema itself (PokeInvest ID, numeric URL ID, or name with best-match resolution). The description adds no additional meaning about the identifier, only about the response. Baseline 3 applies since the schema does all the parameter work.

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 opening clause "What a card sells for" plus the enumeration of grades and providers makes clear this retrieves pricing data for a single card. It is distinguishable from get_price_history and get_sales in emphasis (current median sold prices across graders), though it never explicitly names those siblings. The verb is implicit ("what X sells for") rather than a crisp "get current card prices".

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?

There is no statement of when to call this versus get_price_history, get_sales, get_population, or get_population_history, even though the description mentions population totals and sales that overlap those siblings. No prerequisites or exclusions are given. The agent must infer routing from the return-field list alone.

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