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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), and the description adds real context beyond them: full-series delivery without an API key, the key being needed only for bulk export, and no cap on historical windows. It stops short of describing the response structure or granularity, so it is strong but not complete.

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 rhetorical opening question front-loads intent well, but the text repeats the free/no-quota claim three times and carries a full bilingual restatement plus a '(VR v1.0)' tag. Several sentences could be trimmed without losing guidance.

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?

Covers purpose, alternatives, cost model, and parameter guidance for a three-parameter, zero-required tool with no output schema. The main gap is what the returned series looks like (granularity, units, date alignment), which the agent must infer.

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%, so the baseline is 3; the description adds that the window published in /mercado and /vr is only a default and that any window is free, which changes how an agent should set dias. It restates default 30 and optional categoria, which is redundant but harmless.

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 resource and scope: a historical series of the observed P10–P90 price band by category, framed around whether dispersion is widening or tightening. It explicitly contrasts with point-price tools, so an agent can distinguish it from livestock_prices and value_cattle_lot without opening any schema.

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 explicit routing: 'Valor de HOY → livestock_prices' and 'valuar una tropa → value_cattle_lot', leaving this tool for the historical-band question. Also states access conditions (free last 30 days, unlimited backward, no quota), so the agent knows there is no cost penalty for large windows.

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