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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is fully covered. The description adds only mild context ('now' = current snapshot, 30-day window for new), and says nothing about pagination, ordering stability, or result size beyond what the schema's limit implies.

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 core purpose, then two compact clauses for the enum values and a short optional-filter note. No filler, though the sentence fragments read more like notes than structured guidance.

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, but 'ranked list of Roblox games' conveys the return shape and ordering well enough to call the tool. With annotations covering safety and the schema covering all parameters, nothing critical is missing aside from sibling disambiguation.

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 100%, so all three parameters (list, genre, limit) are already documented in the schema. The description restates the list enum meanings and the single-genre restriction but adds no format or syntax detail beyond the schema; 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+resource: a ranked list of Roblox games, with the two ranking modes (most_played, new) explained. It does not differentiate itself from siblings like rising, trends, or charts, which likely return different rankings, so an agent cannot fully route on purpose alone.

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 clarifies when to pick each list value ('most players right now' vs 'came out in the last 30 days'), which is real selection guidance for the enum. However, it never says when to use this tool instead of sibling tools such as rising, trends, or charts, and gives no exclusions.

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