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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds non-obvious behavior beyond the annotations: gated content returns `locked` with `upgradeUrl`, and output is served as Markdown from public BOE data. This meaningfully helps an agent anticipate paywall-driven responses.

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 front-loaded sentences: the first states the core action and return fields, the second covers access requirements and locked behavior. The enumeration of gated fields (scoring, veredicto, cargas, ROI, valoración, intervinientes) is slightly long but earns its place by telling the agent exactly what to expect.

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 single-parameter read-only tool with full annotations and an output schema, the description covers access level, data source, output format, and paywall gating. Nothing an agent needs to call it correctly — or to set expectations about locked fields — is missing.

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%: the single `id` parameter is already documented as returned by `search` or a record URL. The description confirms the lookup key used but adds no format, syntax, or edge-case detail beyond what the schema already provides, so the 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?

The description states a specific verb and resource: 'Lee una ficha de subasta por `id`' — reads a single auction record by id. It enumerates the return fields (`id`, `title`, `text`, `url`, `metadata`), and the 'compatible con la búsqueda profunda de ChatGPT' plus public-BOE-data focus clearly differentiates it from siblings like `analisis_subasta`, `informe`, or `subasta`.

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?

Clear usage context is provided: 'Pública, sin cuenta' signals no authentication prerequisite, and the schema param description tells the agent the `id` comes from `search` or a record URL, implying the search→fetch workflow. The locked-fields paragraph implicitly warns this tool won't satisfy requests for scoring, verdict, or ROI, but it never names the alternative tool to use for those.

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