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

Annotations already declare readOnly=true, idempotent=true, and destructive=false. The description adds valuable extra behavioral context: payment via prepaid credit, no platform credentials, non-confidential data scope, and LGPD controller responsibility. The credential statement is slightly ambiguous given required login/senha, but it does not contradict the 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 brief and front-loads the main purpose before adding billing and legal caveats. There is minor redundancy between 'consulta em fonte oficial' and 'consulta informação de fontes e órgãos oficiais brasileiros', but overall each sentence earns its place.

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 has 5 parameters, no output schema, and zero parameter descriptions, yet the description does not explain expected inputs, what exactly is downloaded, or the return format. Annotations cover safety, but operational completeness is lacking for an agent to invoke this tool confidently.

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% with 5 parameters, and the description provides no explanation of login, senha, mes, nome_cliente, or codigo_instalacao. The statement 'sem credenciais da plataforma' is also confusing next to the required login/senha fields. The description adds essentially no parameter-level meaning.

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 clearly gives a verb and resource: 'Download, consulta em fonte oficial' and 'consulta informação de fontes e órgãos oficiais brasileiros'. It distinguishes this tool from siblings like authenticate or marketplace as the only data-consultation tool, though it relies on the tool name to convey that this specifically concerns 'contas Light'.

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 provides useful when-to-use context: it is a paid, prepaid-credit query against official Brazilian sources, does not require platform credentials, and excludes confidential data. It does not explicitly name alternative tools or when not to use it, but the context is clear enough for a tool with these siblings.

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