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

Annotations already set readOnlyHint, idempotentHint, and destructiveHint=false, and the description adds substantial behavior beyond that: returns initial/final values, % change, min, max, number of sessions, and a ~8-point sample; explains index conversion rules (dolar blue venta) and recortado:true truncation behavior. There is no contradiction 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 dens but well front-loaded with the core series and return metrics before moving to range, currency, limits, and alternatives. Every sentence carries useful information, though the single long paragraph could be structured into bullet points for easier parsing.

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?

With no output schema, the description carries the full burden of explaining return values, and it does so clearly (initial/final, variation %, min, max, number of sessions, sample). It also covers limits, authentication options, price/upgrade paths, and relevant sibling alternatives, making it complete for correct invocation.

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 the baseline is 3; the description adds operational meaning such as 'GRATIS a cualquir profundidad' for from/to exact dates and the recortado:true output flag when exceeding 365 days. It mostly reinforces schema details rather than inventing new param semantics, so a 4 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 and resource: 'Serie histórica del Índice Novillo (INMAG) — TENDENCIA.' It clearly describes what the tool does, including the daily index, source history, and computed summary statistics. It also distinguishes itself from siblings by saying today's value goes to get_indice_novillo and weekly category data goes to get_precios_hacienda.

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 when-to-use guidance: use this for historical daily INMAG series, get_indice_novillo for today's value, and get_precios_hacienda for weekly category data. It also clarifies range mechanics (dias vs desde/hasta), free limits, truncation behavior, and paid upgrade paths, so an agent knows exactly when this tool applies.

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