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 covered. The description adds a genuinely new behavioral constraint beyond them: the call only works for members of the pool, which an agent must know before invoking it.

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 statement, then a single dense enumeration of returned sections, plus a short constraint sentence. The long parenthetical listing is heavy but every clause names a distinct part of the payload rather than padding.

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 no output schema, the description does the work of describing return content, which is valuable. But it omits practical call-level details an agent would want — what happens if the caller is not a member, and whether ranking/matchday sections can be large or paginated.

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% and there is a single required parameter, so the schema already explains pool_id and even points at list_pools as its source. The description adds no format or sourcing detail beyond that, so the baseline of 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 ('Una peña del jugador al detalle') and enumerates the exact contents returned: annual ranking, handicap and movements, jackpot, rules, and matchdays. This clearly distinguishes it from list_pools, which only enumerates pools.

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?

Adds an access prerequisite ('Solo si es miembro'), which is useful context. However, it never explicitly says when to use this instead of list_pools or another sibling, nor does it state what to do if the user is not a member — the guidance is implied rather than spelled out.

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