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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds context by clarifying that the data is 'ACESSO PÚBLICO' and not private, and explains the prepaid credit model and lack of credentials. This goes beyond the structured annotations, though it does not describe all response behavior.

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 three sentences, each with a distinct role: purpose, operational model, and legal/data source context. It is concise and well-structured, 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?

The description adequately covers the tool's purpose, data source, access method, and legal responsibility, which is rich context for a simple enrichment tool. The only notable gap is the undocumented 'completo' parameter, but overall the description is sufficiently complete for an agent to understand the tool's 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?

The description mentions 'celular' and 'email' as the basis for enrichment, aligning with the required properties. However, it does not explain the 'completo' boolean parameter, and with 0% schema description coverage, the description fails to fully compensate for the parameter semantics. It adds no format or behavior details for the parameters.

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 states 'Enriquece um contato a partir do celular e do email, retornando os dados cadastrais associados,' specifying the action (enrich), inputs (cell phone and email), and output (associated registration data). It distinguishes from sibling tools like authenticate and marketplace, which serve entirely different purposes.

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 usage context: 'Hospedado pela plataforma, sem credenciais, pague por consulta com crédito pré-pago' explains the operational requirements. It also notes the legitimate purpose under LGPD, but does not explicitly compare to alternatives or state when not to use, so it falls short of a 5.

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