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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is established. The description adds valuable behavioral nuance beyond that: 'Devuelve siempre solo subastas activas' and the caveat that cargas_ratio_max 'solo poda las subastas con cargas numéricas'. This is exactly the kind of non-obvious behavior an agent needs, and nothing contradicts the annotations.

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 description is front-loaded with a one-line purpose, followed by a compact bullet list giving each parameter just enough semantics, and a short paragraph for location exclusions and the always-active behavior. Every sentence earns its place; there is no filler or redundancy despite covering a 15-parameter tool.

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 15-parameter search tool with no required arguments and no output schema, the description covers the essential invocation context: optional filters, value examples, location semantics, the no-free-text limitation, and the always-active-auction guarantee. It is slightly incomplete on the omitted price/m2 parameters and does not describe the result shape, but that is minor for a list-style search tool with sibling tools for details.

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 0%, so the description carries the burden and does so well: it explains uso, bien_subtipo, tipo_subasta, descuento_min, dias_max, cargas_ratio_max, orden, limit, and the three location filters with examples, units, and constraints. It never mentions precio_min/precio_max/m2_min/m2_max, although these are inferable from their names, so it is not fully complete.

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?

The first sentence names a specific verb and resource: 'Busca inmuebles en subasta pública activa en España (BOE, AEAT y Seguridad Social)'. This clearly identifies the tool as a search over active public-auction properties in Spain from concrete sources, which is distinct enough from siblings like detalle_inmueble or comparar_inmuebles even without naming them.

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 gives clear context: all filters are optional. It also explicitly states what the tool does not do ('No hay búsqueda por texto libre ni parámetro de ubicación genérico'), redirecting to municipio/provincia/codigo_postal. However, it never names sibling tools or states when to use an alternative, so it misses the explicit when-not guidance required for a 5.

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