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

Annotations already declare a safe read (readOnlyHint, idempotentHint, destructiveHint=false), so the bar is lower; the description still adds real context beyond them: data provenance (official PS and Xbox Store listings), currency conversion at the official exchange rate, and tax treatment including the interpretation rule that a pre-tax price is labelled and never presented as cheaper. It omits freshness/staleness of listings, which would have been the last useful piece.

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 payoff (what a buyer pays) followed by scope, sources, and the three return components, then a short non-affiliation clause. Dense but every clause carries information; the affiliation disclaimer is the only borderline element, and it is brief.

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 must describe returns itself and it does: local-currency checkout price, USD equivalent at the official rate, and tax inclusion status. Combined with the market count and edition scope, an agent has everything needed to call it 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 coverage is 100%, so both parameters are already documented in the schema (country accepts name or two-letter code; platform enum restricts to one store). The description only reinforces the country scope ('one of 63 markets') and adds no format or edge-case detail beyond the schema, so the baseline 3 applies.

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 a buyer pays for GTA 6 in one of 63 markets, drawn from PlayStation and Xbox Store listings. It also scopes the two editions covered (Standard and Ultimate), which separates it cleanly from siblings like compare_editions and release_info.

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?

Usage is implied rather than stated: the singular-country framing ('in one of 63 markets') and the platform 'Omit it for both' note signal a per-country lookup, but no sibling is named and no when-not-to-use condition is given (e.g. use compare_editions to rank editions against each other). Adequate but leaves routing to inference.

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