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

Annotations already declare readOnlyHint and openWorldHint, and the description adds genuinely non-obvious behavior: the AND-matching semantics across category/group/name and the fallback when the result set is empty. It repeats the return fields that the output schema already documents, which is redundant rather than harmful.

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 matching rule, then examples, then the failure-recovery tip — a sensible order an agent can scan. The five-example list is slightly longer than needed and the sentence restating returned fields duplicates the output schema.

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 read-only search over a large catalog, the description covers query construction, filtering, and empty-result handling, and an output schema exists so return shape need not be spelled out. The only real omissions are the undocumented `limite` parameter and any hint that the returned code should be fed to the sibling `serie`.

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 0%, so the description has to carry the load and largely does: it explains `texto` as an all-words-must-match search and enumerates valid `frecuencia` values that the schema itself declares only as a bare string. The third parameter, `limite` (default 10), is never mentioned, leaving that gap to the schema's default value alone.

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?

Names a specific verb and resource ("Busca series del BCRP") and even specifies the matching rule — all words must appear in category, group, or name — which is far more precise than the title alone. It never distinguishes itself from the sibling `serie` (singular), so an agent gets no explicit routing signal about which of the two to pick.

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 five concrete query examples and the accepted frequency values, plus an explicit recovery strategy ("Si no hay resultados, prueben con menos palabras"), which tells the agent how to retry rather than guess. It stops short of stating when NOT to use this tool or naming `serie` / `resumen` as the alternative once a code is known.

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

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

The annotations already establish that this is a read-only, open-world operation, so the description does not need to repeat safety details. It adds useful context by stating that only coincident periods are used and that correlation does not imply causality, but it does not disclose error behavior or handling of non-overlapping ranges.

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 a single front-loaded sentence with no filler. Every clause contributes either the core operation, the period constraint, or the no-causality caveat.

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?

The tool takes four required parameters, has no schema descriptions, and performs a comparison whose correctness depends on overlapping date ranges and valid series codes. The description names the core operation and caveat, but it leaves parameter formats and edge-case behavior unspecified, which is a significant gap for an agent to call it correctly.

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 0%, so the description must compensate for four undocumented required parameters. It conveys the high-level meaning of two series and a period, but never specifies what 'codigo_a'/'codigo_b' look like or what date format 'desde'/'hasta' require.

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?

The description states a specific operation: it compares two series over coincident periods and calculates their correlation. It implicitly distinguishes itself from the single-series sibling 'serie' by requiring two series, but it does not explicitly name or route against 'buscar_series' or 'resumen'.

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?

There is no explicit guidance on when to use this tool versus the sibling tools, nor any when-not conditions. The phrase 'por periodos coincidentes' implies a constraint, but the description does not say what to do if periods do not overlap or when 'serie' would be more appropriate.

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

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that the statistics are 'exactas' and lists the metrics computed, but it does not describe behavior around missing data, invalid codes, date range constraints, or other runtime characteristics.

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 a single front-loaded sentence with no filler. Every phrase contributes to stating the computation and its scope.

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?

An output schema exists, so return values do not need description coverage. However, with three required parameters at 0% schema coverage, no explicit usage routing, and an openWorldHint, the description leaves too much unexplained for an agent to reliably select and invoke the tool.

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 0% for three required parameters, so the description must carry parameter meaning. It only loosely implies a series identifier ('de una serie') and a date range ('del periodo'); it never names codigo, desde, or hasta, nor explains their formats or constraints.

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?

The description states a specific verb and resource: 'Calcula estadísticas exactas de una serie', and enumerates the statistics (extremos, cambio, variación, promedio) plus the period scope. It is clear what the tool does, but it does not explicitly differentiate itself from siblings such as serie or comparar_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?

There is no explicit when-to-use guidance, no when-not-to-use guidance, and no mention of alternatives. The agent can infer that this is for summary statistics over a period, but the description does not route it against buscar_series, serie, or comparar_series.

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

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds useful behavioral context beyond annotations: both dates are inclusive, data is official BCRP data, and the result includes data, series metadata, and a reproducible source link. It does not cover error behavior or rate limits, but the main behavioral profile is clear.

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?

Three compact sentences, front-loaded with the core action and followed by essential date-format guidance and return contents. Every sentence adds useful information without repetition or filler.

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?

The tool is simple and has an output schema plus annotations, so the description need not explain return structure. Still, for a 3-required-parameter tool with 0% schema coverage, the missing explanation of the codigo parameter's format is a clear gap 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 0%, so the description must carry parameter meaning. It does explain the date formats for desde and hasta depending on series frequency (YYYY-MM, YYYY-T1, YYYY-MM-DD, YYYY), which is valuable. However, it never specifies the format or expected form of the required codigo parameter, leaving a key parameter only partially documented.

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: downloads official BCRP series observations for one series over a date range. This inherently distinguishes it from sibling tools like buscar_series, resumen, and comparar_series, which search, summarize, or compare rather than download a single 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?

The description implies usage by specifying a single series code and an inclusive date range, and gives date formats by frequency. However, it does not explicitly say when to use this tool instead of buscar_series or comparar_series, nor does it state prerequisites such as needing a valid series code.

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