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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds value beyond these by disclosing the endpoint path, a 1-hour cache (freshness expectation), and the aggregation use case. 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?

Three short sentences with the purpose front-loaded and every sentence earning its place: main function, endpoint and filter parameter, aggregation use case, and cache behavior. No filler or redundancy.

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 filtered-list tool, everything an agent needs is present: purpose, distinguishing filter, pagination parameters in the schema, safety profile in the annotations, and return shape in the output schema. The cache disclosure covers the only nontrivial runtime behavior not otherwise stated.

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 all four parameters (ano, pagina, tamanho_pagina, codigo_classificacao_superior) are already documented. The description adds some semantic color by framing codigo_classificacao_superior as the category aggregation filter with an IT-items example, but does not add syntax-level details beyond the schema. Baseline 3 applies.

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 opens with a specific verb and resource ('Lista itens de PCA') and names the distinguishing filter ('por categoria superior do item' via codigoClassificacaoSuperior). This clearly differentiates it from sibling tools like compras_pncp_pca_listar without needing to inspect the 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?

Provides a concrete use case ('agregar planejamentos por categoria, ex.: todos os itens de TI planejados para o ano'), which tells an agent when the tool is appropriate. It does not explicitly name exclusions or the alternative unfiltered PCA listing tool, so it stops short of full when-not-to-use guidance.

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