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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavior context by naming the aggregated sources (Plataforma de Contratación, TED, BOE) and the returned fields, but says nothing about pagination limits or result volume, keeping it at a solid 3.

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?

Two tightly packed sentences with no filler: the first states what is searched and the scope, the second states the return payload. Front-loaded and efficient.

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 10-parameter tool with no output schema, the description helpfully enumerates the returned fields (objeto, órgano, importe sin IVA, fecha límite), covering the missing return documentation. The main remaining gap is explicit sibling differentiation, but nothing needed to call the tool is absent.

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%, so all ten parameters are already documented in the schema, which sets the baseline at 3. The description adds no parameter-level detail (e.g., that 'orden' affects ranking or how província/cpv interact) beyond the return fields it lists.

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 description names a specific verb (buscar) and resource (contratos públicos de España) and scopes it to open-bidding listings, which implicitly separates it from buscar_adjudicaciones (already-awarded contracts). It does not explicitly name or contrast with the siblings, so it stops short of a 5.

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 only implied by 'plazo de ofertas abierto' — the agent can infer it should use this tool for live tenders versus awarded ones, but there is no explicit when-to-use, when-not-to-use, or alternative routing among buscar_adjudicaciones, buscar_convocatorias, and ver_convocatoria.

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