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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered externally. The description adds genuine context beyond that — prices derive from completed sales, and the region/edition arguments are values echoed back from a prior answer, implying a chained call pattern. It says nothing about empty results, games without sales history, or caching/staleness of prices, which matters for a read-only analytical tool.

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?

Front-loaded with the outcome ('What one game sells for, from completed sales') followed by the facets, then the invocation instruction. Dense and largely waste-free, though the middle enumeration ('each region's and each edition's price') is slightly awkward to parse.

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?

There is no output schema, so the description carries the burden of describing return values — and it does, covering condition-tier ranges, typical prices, per-region and per-edition prices, sell-through speed and newest sales. Combined with the fully documented 5-parameter schema, an agent has enough to call this correctly.

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 description coverage is 100%, so every parameter including defaults, bounds and the region/edition dependency is already documented in the schema. The description only restates that region and edition are optional and that the URL comes from search_games. Baseline 3 is appropriate since the schema does the heavy lifting.

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 and resource: what one game sells for from completed sales, then enumerates the exact breakdowns returned (condition tiers, region, edition, sales velocity, newest sales). This is clearly distinguishable from the sibling browse/list/search tools, and it explicitly names search_games as the source of the input.

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?

Establishes the prerequisite workflow — the game must be named by its page URL obtained from search_games — and says region and edition are optional refinements. It does not state when this tool should NOT be used or what to do if a game has no sales data, so it stops short of full conditional guidance.

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