Get global achievement rates

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

Beyond the readOnlyHint annotation, the description discloses ordering (most-common first), a cap (first 200), the need to check `returned` vs `count`, error behavior (empty list for unknown/no-schema appids), and that no API key is required. This richly informs the agent's expectations.

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?

The description is information-dense yet well-structured. Each sentence adds unique value: purpose, return data and limitations, edge-case behavior, source of appid, and authentication. No filler or redundancy.

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 tool with one parameter, an output schema, and annotations, the description covers return fields, ordering, limits, error handling, and data source. It is fully sufficient for an agent to invoke this tool correctly without additional external knowledge.

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 input schema provides 100% coverage, including a description for appid ('Steam application id (appid). Get it from search_games.'). The tool description repeats 'by appid' and 'Get the appid from search_games' but adds no new meaning beyond the schema, so the baseline of 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?

The description states a specific verb ('Get'), a resource ('global unlock percentage of each achievement'), and a scope ('by appid'). It clearly differentiates from the sibling get_game_achievements by noting it returns internal names and unlock percentages rather than display names/descriptions.

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?

Explicitly directs users to get_game_achievements for display names/descriptions, references get_game_news for similar behavior on unknown appids, and instructs to obtain appid from search_games. This provides clear when-to-use and alternative context.

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