Resumen

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

readOnlyHint and openWorldHint already establish that this is a safe, external-data read, so the description needn't restate safety. It adds the aggregate outputs it computes, but says nothing about what happens with empty/invalid ranges, unavailable series codes, or return shape (covered by the output schema).

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 definition, then the usage rule, then a compact example — no filler. The 'Mismas fechas que serie' fragment is terse to the point of being slightly cryptic without the sibling's docs.

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 an output schema present, the description doesn't need to explain return values, and its job is mainly invocation guidance, which the example covers well. What's missing is minor: date-range boundary behavior and how failures on unknown codes surface.

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 0%, so the description must carry parameter meaning — and it largely does: the worked example 'resumen("PD04638PD", "2026-01-01", "2026-10-15")' fixes argument order, shows the expected series-code form, and establishes ISO date format. Only the semantics of 'desde'/'hasta' inclusivity is left unstated.

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 ('Resume') on a specific resource (a BCRP series over a period) and enumerates exactly what the summary contains: first/last value, change, % variation, average, max, min. That enumeration alone separates it from the sibling 'serie' tool, which returns the raw series.

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?

'Úsenla siempre que la pregunta pida una variación, un promedio o un extremo, en vez de calcular a mano' gives an explicit selection rule, and 'Mismas fechas que serie' points to the related tool for date alignment. It stops short of naming conditions under which to prefer 'serie' or 'buscar_series' instead.

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