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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds behavior the annotations cannot convey: it returns cross-source id mappings (important since there is no output schema) and accepts up to 100 ids per call. It stops short of saying what happens when an id is unknown or unmatched.

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 core behavior is front-loaded in the first sentence and the operative constraints (URL-form ids, comma-separated, 100 max) follow. The 26-item source enumeration is long and largely redundant with the schema enum, which is the main drag on conciseness, but every other sentence earns its place.

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?

For a two-parameter, fully required, read-only lookup with no output schema, the description covers input format, batch limits, supported sources and the shape of the result. Only edge-case behavior (unknown id, partial or ambiguous matches) is left unaddressed.

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 50%, but the gaps that matter are filled: the description documents the 100-id comma-separated batch ceiling, which the schema does not, and clarifies that ids are accepted in the exact form found in store URLs. The enumerated source list duplicates the enum rather than adding new meaning, but the id-format semantics are real added value.

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: given one external store/database id, find the game record and return its ids in all other sources, with a concrete example (Xbox id -> Steam appid). This makes the lookup-vs-search distinction reasonably clear, though it never names or contrasts with the siblings (ficha_juego, buscar_juegos) that an agent must choose between.

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?

Usage is implied rather than stated: the tool applies when you already hold an id from a store or database, and 'Vale el id tal como aparece en la URL de la tienda' is a genuinely useful input hint. There is no explicit when-not guidance and no reference to the sibling tools that handle name-based search or full record retrieval.

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