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

Annotations already carry readOnly/idempotent/openWorld, so the bar is lower; the description still adds real context: data starts 2015, methodology (ratio over centered 12-month moving average, median across years, normalized to 1.00), and the deliberate USD-vs-pesos choice. It also discloses the default month behavior. Missing only coverage of edge cases or compute cost.

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-loaded with the core question, then methodology, then args, then rationale — a sensible order. The bilingual restatement adds length that partially duplicates the Spanish, but it is functionally tight and each substantive sentence (methodology, USD rationale) earns its place.

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 usefully tells the agent what the returned index means (normalized to 1.00, ratio vs 12-month moving average), which enables correct interpretation of results. Complete for a single-optional-param read tool, though it doesn't describe the exact output fields/shape.

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 baseline is 3; the description adds value beyond the schema by stating the default for `mes` ('default el último con índice'), which the schema only labels 'opcional'. Format YYYY-MM is already in the schema, so no extra credit there.

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 precisely what it computes: a seasonal index of Argentine cattle prices in USD by month (since 2015), plus where today sits against that norm. It implicitly distinguishes itself from daily-price tools by contrasting 'que es lo que el precio del día NO contesta', though it doesn't name the specific sibling (livestock_prices / cattle_price_index).

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 a clear decision context ('¿conviene comprar ahora o esperar?') and frames it against the daily price tool as the alternative for a different question. Lacks an explicit 'when-not' or prerequisites statement, but the use case is unambiguous.

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