Get global achievement rates

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

Annotations already indicate readOnlyHint and openWorldHint. The description adds that it 'Works without a key', disclosing an important authorization trait. It also describes what the tool returns (global unlock percentages), which is consistent with the read-only nature. No contradictions.

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 three sentences, each serving a clear purpose: stating the action, defining the output, and providing source/access info. It is front-loaded with the primary purpose and contains no extraneous words.

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?

Given the tool's simplicity (one parameter, no output schema, clear annotations), the description covers the main points: what it does, how to get the input, and that it's open. It does not explicitly describe the output format (e.g., a list of achievements with percentages), but the nature of the data is implied. Slightly more detail would make it fully complete.

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 schema covers 100% of parameters and includes a description for appid ('Steam application id (appid). Get it from search_games.'). The description repeats this guidance but does not add new meaning beyond the schema, so a baseline score of 3 is appropriate.

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 clearly states the verb 'Get', the resource 'global unlock percentage of each achievement', and the context 'by appid'. It explains what the data represents ('how rare each achievement is across all players'), distinguishing it from sibling tools like get_game_achievements (which likely lists achievements without percentages) and get_player_achievements (player-specific rates).

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 description tells users to get the appid from search_games and notes that the tool works without a key, providing essential usage context. However, it does not explicitly state when not to use this tool versus alternatives like get_game_achievements or address any prerequisites beyond the appid.

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