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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds meaningful operational details beyond those annotations: the upstream contract requiring both codigo and tipo, and the 15-minute cache, which informs the agent about freshness. 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 compact and front-loaded: purpose first, then the required parameter combination, accepted types, and cache note. Every sentence contributes useful information with no 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?

For a two-parameter read-only consult with a rich input schema and an output schema, the description covers the essential call requirements and a staleness caveat. The only notable gap is the lack of explicit navigation among the large sibling set, but the endpoint and parameter semantics provide enough orientation.

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, but the description adds value by flagging that the upstream requires codigo + tipo even though the schema marks tipo optional with a default. It also enumerates the only accepted type values, helping an agent avoid unsupported identifier formats.

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 first sentence, 'Consulta um contrato no Dados Abertos (endpoint 1.1)', states a specific verb and resource with an endpoint qualifier that helps separate it from legacy or Comprasnet contract tools. It does not explicitly name sibling tools, so it stops short of a 5.

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 gives useful invocation context: the upstream requires 'codigo + tipo' and lists the accepted type values. However, it does not say when to prefer this tool over closely related siblings such as compras_contrato_comprasnet_consultar or compras_contratos_listar, so the usage guidance is implied rather than explicit.

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