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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuine context the annotations lack: that results are the 'lowest listed' price (aggregation semantics) and that each entry carries a comparison link, plus a docs URL.

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?

A single dense sentence front-loads the core behavior (lowest price, batch of 50, keyed by app ID) and ends with a docs pointer. Nothing is redundant and nothing needed is buried.

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?

With no output schema, the description usefully notes that each game comes back with a comparison link, so the return shape is partly disclosed. It is a simple one-parameter read tool, so remaining gaps (e.g. behavior for unknown IDs, rate limits) are minor.

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 there is a single parameter, so the schema already documents the array of integer Steam app IDs and its 1-50 bounds. The description only reinforces that these are Steam app IDs and hints at the wishlist use case, adding little beyond the structured data.

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 ('lowest listed prices for ... PC games') with the batching scope ('up to 50 ... at once') and the lookup key ('by Steam app ID'). The batch limit implicitly separates it from the single-game sibling lookup_game_price, though the sibling is never named.

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?

The parenthetical '(e.g. a wishlist)' plus the 50-item cap implies bulk/batch use, from which an agent can infer that single lookups belong to lookup_game_price. However, no explicit when-to-use, when-not, or named alternative is given.

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