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

Annotations already declare readOnlyHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds that the response includes situação, linha digitável, PIX copy-and-paste, and official PDF in base64, and that PDF inclusion is conditional, which is useful behavioral context beyond 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?

Single sentence that front-loads the action and lookup method, then lists return fields. 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?

Output schema and annotations cover return shape and safety, but the description does not compensate for undocumented TipoAmbiente, which matters for an open-world query that can target different environments. It also omits error/not-found behavior.

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 50%, and the description only echoes the two lookup keys ('Id ou identificador interno') without adding syntax or constraints. It does not explain TipoAmbiente or IncluirPdf beyond what the schema already states, leaving half the parameters underexplained.

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 ('Consulta') and resource ('GNRE'), identifies the two lookup keys, and lists the returned data. It is clearly a query tool distinct from gnre_emitir, but it does not explicitly name a sibling or state when to choose it.

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 the tool is for fetching an existing GNRE by ID or internal identifier, but it does not state when to use it over gnre_emitir or gnre_configuracao, nor does it mention prerequisites. The schema's Id description carries the fallback logic, not the tool description.

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