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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lowered. The description nonetheless adds a data-scope constraint not present in annotations ('solo empresas, no personas físicas'), which prevents wasted queries. It does not describe return format, but that is a minor gap against the annotated safety profile.

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 tight sentences: what it is, what it is for, and the hard scope limit. The resource definition is front-loaded and every 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 read-only search tool with a fully documented schema and no output schema, the description is nearly complete. What remains missing is any hint of the result shape (e.g., contract fields returned), which an agent might want given there is no output schema.

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%, including the important subtlety that 'Con NIF se ignora el texto'. The description only restates the query axes and adds no syntax or precedence detail beyond the schema, so 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+resource in Spanish: 'Contratos públicos ya adjudicados' (already-awarded public contracts), with the search axes (NIF, texto, provincia). This clearly distinguishes it from siblings buscar_licitaciones and buscar_convocatorias, which cover pre-award stages.

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 ver qué gana una empresa y cuándo vence cada contrato' gives a concrete use case, and 'Solo empresas: no hay datos de personas físicas' is an explicit scope exclusion. It does not name the sibling alternatives directly, so it stays below a 5.

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