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

Annotations already declare readOnlyHint=true, and the description adds valuable context beyond that: 'No requiere iniciar sesión' (no login required) and the fact that it is a read operation for summarizing. It clearly describes what data is returned, aligning with the read-only nature. No contradictions with 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 concise—two sentences—and front-loaded with the core function first. It efficiently covers purpose, input source, returned fields, use case, and authentication in a compact manner with no redundant content.

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 simple tool with one parameter, no output schema, and read-only annotations, the description is complete. It lists the key return fields (organismo, importe total, número de concesiones y beneficiarios, principales beneficiarios), explains the input source, and states use case and authentication, which is sufficient for an agent to invoke it correctly.

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 100% with the parameter 'codigo' already described. The description adds meaning by explaining where the code comes from: 'el que aparece en el enlace /subvencion que devuelve buscar_oportunidades', which helps the agent know exactly how to obtain a valid input. This goes beyond the schema's basic description.

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 clearly states the verb 'Devuelve el detalle completo' (returns the complete detail) and the resource 'UNA convocatoria de subvenciones (BDNS)' with its input code. It distinguishes from siblings by specifying it handles a single convocatoria and explicitly mentions the link source from buscar_oportunidades, setting it apart from tools like detalle_licitacion.

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 explicitly says 'Úsala para resumir una subvención sin salir de Boletín Claro' (use it to summarize a grant without leaving Boletín Claro), providing a clear use context. It also notes the prerequisite of obtaining the code from buscar_oportunidades, but does not explicitly mention when not to use it or name alternatives, though the sibling tool detalle_licitacion implies a different resource type.

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