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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds significant behavioral context beyond these: it is hosted on the platform, requires no credentials, involves prepaid credit, accesses public data (not private), and places LGPD compliance on the client. This informs the agent about operational and legal aspects that annotations do not cover.

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, consisting of two sentences. The first sentence states the core function and inputs, and the second adds necessary operational and legal context. Every word earns its place; no redundancy or irrelevant details.

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 covers the main purpose, key inputs, and critical operational/legal context (public data, no credentials, pre-paid, LGPD). However, it fails to explain the 'completo' parameter, does not specify the output format (just 'Emite a Certidão'), and contains the 'ou' discrepancy regarding CPF/CNPJ. These gaps make it only partially complete.

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%, so the description must compensate. It mentions CPF/CNPJ, IM, and Município but misleadingly says 'a partir do CPF ou CNPJ' (from CPF or CNPJ) while the schema requires both Cpf and Cnpj. This is a contradiction that could cause incorrect invocation. The optional parameter 'completo' is not mentioned at all, leaving its meaning undefined.

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 the tool's function: 'Emite a Certidão Negativa de Débitos municipal de uma pessoa ou empresa a partir do CPF ou CNPJ...' It uses a specific verb (emite) and identifies the resource (certidão negativa de débitos municipal). This distinguishes it from the unrelated sibling tools (authenticate, connect, marketplace, etc.).

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 context of use is implied: to obtain a municipal negative debt certificate from public sources. The description adds operational context (hosted, no credentials, pay-per-query, LGPD responsibilities) but does not explicitly state when to use this tool versus alternatives or when not to use it. No alternatives are mentioned, so usage guidance is implied but not directed.

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