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

Beyond the annotations (readOnlyHint, idempotentHint, destructiveHint), the description discloses payment per query ('pague por consulta com crédito pré-pago'), the non-confidential nature of the data ('não é dado sigiloso'), and LGPD responsibility. This adds meaningful behavioral context without contradicting 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 concise, with the key action and resource front-loaded in the first sentence. The remaining two sentences add relevant context (hosting, payment, LGPD) without unnecessary elaboration.

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?

With 4 parameters, no output schema, and no parameter explanations, the description is insufficient for an agent to invoke the tool correctly. It lacks return behavior, parameter semantics, and operational details, despite providing some high-level context.

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%, and the description does not explain any of the four parameters (email, senha, instalacao, unidade_consumidora). It even creates ambiguity by stating 'sem credenciais da plataforma' while requiring email/senha, leaving users to infer these are external credentials.

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 'CPFL: Download, consulta em fonte oficial,' identifying a specific resource (CPFL) and actions (download/query). It distinguishes itself from generic sibling tools like authenticate or marketplace, though it could be more explicit about what is being consulted (e.g., utility bills).

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 no direct guidance on when to use this tool compared to alternatives. It mentions 'sem credenciais da plataforma' and the prepaid payment model, but these are operational traits, not explicit use-case instructions or exclusions.

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