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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety is covered. The description adds real context beyond that: output is strictly aggregated (client counts per game, never identifying who), which tells the agent it must not expect or request user-level data.

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?

Three short sentences, front-loaded with the core definition before the aggregation caveat and the use case. Slight overlap between the naming of the two metrics and the closing recommendation sentence, but nothing is wasteful.

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?

A 3-parameter, optional-only, read-only tool with no output schema. The description conveys the ranking nature, the two metrics, and the aggregate return content, which is sufficient for correct invocation; only the ordering/tie-breaking behavior of the ranking is left unspecified.

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 coverage is 100% — limit, metric and country are all fully documented in the schema, including defaults and enum meanings. The description restates the wanted/favorite distinction but adds no syntax or constraint beyond what the schema already provides, so the 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 resource and scope: a community ranking of games split by two metrics (los más deseados / favoritos de clientes). An agent can tell this is an aggregate-ranking tool rather than a catalog search, though it never names a sibling (e.g. search_games) to sharpen the boundary.

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?

"Sirve para recomendar 'lo que más gusta' o 'lo que más se desea'" implies the use case (recommendation/queries about community preference), which is genuinely helpful. However it gives no when-not-to-use rule and never points to alternatives like search_games, leaving the routing implicit.

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