fetch_reference

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds meaningful behavior beyond that: data is cached locally on this machine, only derived measurements are returned, and raw texts remain in the local cache for the anti-copy check. This helps the agent understand what it will and won't receive.

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?

Two sentences, front-loaded with the core action and resource, followed by the scope of returned data. No filler, though the return-value summary slightly overlaps with the output schema.

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?

An output schema exists so return values need not be detailed, and annotations cover the safety profile. However, the tool still lacks usage context and any explanation of the 'tags' and 'refresh' parameters, leaving gaps for a 3-parameter tool with 0% schema coverage.

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 0% across three parameters. The description alludes to caching (relevant to 'refresh') but never explains 'refresh' semantics, and it says nothing about the 'tags' filter or 'appid'. With zero schema coverage, the description fails to compensate for the parameter documentation gap.

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 and resource ('Fetch a successful Steam game's public data') and scopes the output ('return derived measurements only: description structure and length, media counts, categories, achievement count/style/distribution'). It does not explicitly distinguish itself from siblings like store_lookup or compare_games, but the 'derived measurements only' framing makes the purpose recognizable.

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?

There is no explicit when-to-use guidance and no named alternatives. The agent must infer that this tool is for gathering reference/benchmark data for a successful game, but nothing states the conditions under which it should be chosen over store_lookup, study_market, or compare_games.

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