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

Annotations indicate readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description doesn't need to restate that it's read-only. However, it adds useful context: it's hosted on the platform, requires payment with prepaid credits, and returns non-confidential official data. It also mentions LGPD data controller responsibilities. This adds behavior beyond annotations, but misses details like rate limits or response format.

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 a single long paragraph, moderately sized. It leads with the tool's purpose and then adds practical information about payment and legal compliance. It's not excessively verbose, but it doesn't use bullet points or short sentences, and some sentences are filler. It earns a passing score for being efficient enough.

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 3 optional parameters, no output schema, and useful annotations. The description covers the query purpose and payment model, but ignores what the output will look like (since no output schema exists), and it doesn't explain the parameter semantics. For a tool that queries official data, knowing the response structure is crucial, but it's not mentioned. It also doesn't mention any limitations or edge cases.

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 0%, so the description must explain the parameters. It mentions 'cpf', 'cnpj', and 'perdcomp' in the schema, but the description does not describe them at all. It only mentions 'consulta' and data sources. With three parameters and zero coverage, the description heavily undercompensates: it gives no clue as to what each param means, whether they are optional, or how they are used.

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 name is descriptive but opaque ('receita_federal_perdcomp_consultar'), and the description says 'DCOMP, consulta em fonte oficial' which clarifies it queries PER/DCOMP data from official sources. It lacks a clear verb+resource structure, but the phrase 'consulta informação de fontes e órgãos oficiais brasileiros' indicates it retrieves info. It does not distinguish from siblings, which are unrelated system tools, but purpose is somewhat clear.

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 explains the commercial context (payment with prepaid credits) and mentions it's the same data available to citizens, but gives no guidance on when to use this tool versus alternatives. It doesn't mention when to use it, when not to, or any prerequisites. Sibling tools are unrelated (auth, marketplace, etc.), so no differentiation is needed, but the description still lacks explicit usage context.

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