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

Beyond the readOnly/idempotent annotations it discloses the access model (public, no account), the gated features (scoring, veredicto, cargas, ROI, valoración, intervinientes need Pro), and the exact failure behavior (`locked` + `upgradeUrl`). This is substantive behavioral context an agent cannot get from 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?

Front-loads the verb, resource, and returned fields before moving to access rules. Dense but every clause carries signal; only the field enumeration slightly overlaps with what the output schema already provides.

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-param lookup with an output schema and read-only annotations, the description covers everything an agent needs: availability, account gating, and the locked/upgrade response path. No meaningful gaps remain.

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?

With a single parameter at 100% schema coverage, the schema already documents that `id` is returned by `search` or can be a ficha URL. The description restates this rather than adding format or edge-case detail, so the baseline 3 is appropriate.

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 (read/lee) and resource (a single auction record by id), and enumerates the returned fields (`id`, `title`, `text` in Markdown, `url`, `metadata`). It is clearly a single-record fetch that consumes an id produced by `search`, distinguishing it from the search/browse siblings.

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?

Gives clear context: public access with no account needed, and notes id comes from `search` (or a ficha URL). It also states which capabilities need a Pro account. It does not explicitly name when to prefer this over siblings like `subasta`, so it stops short of full routing guidance.

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