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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that the output is aggregation counts and notes the page*page_size<=10000 constraint, but offers no other behavioral context such as rate limits or return shape. With annotations carrying the safety burden, a 3 is appropriate.

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 facet enum list appears twice (once as a standalone enum then again in the 'facet: Required facet to aggregate' restatement), and the page constraint duplicates the schema. Purpose is front-loaded, which is good, but the repetition wastes space.

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?

With an output schema present, the description need not explain return values, and it adequately covers the aggregation purpose, the required facet, and the search alternative. For a 29-param read tool whose schema is fully documented, this is complete enough.

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 the schema already documents facet, page, price_tier, and all 29 parameters. The description merely repeats the facet enum and page constraint verbatim, adding no syntax or meaning beyond what the structured fields provide. 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: 'Returns terms aggregation counts for the PlayStation games dataset.' It also names the sibling search tool, so an agent can distinguish faceting from search without opening either schema.

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 closing sentence explicitly routes the agent to datasets_playstation_games_search for searching, which clearly separates this facet-count tool from full search. It does not state when aggregation is preferred, but the context is clear enough.

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