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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds value they cannot convey: the shape of the response payload (a list of candidates, not a single match) and the commercial cost ('Consome 1 requisição', 'Todos os planos'). It does not mention pagination, result caps, or behavior on zero matches.

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?

Three short sentences with zero filler: capability first, then next step, then cost/availability. Every clause carries information an agent needs, and nothing is buried mid-sentence.

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 no output schema, the description properly compensates by naming the returned fields and indicating a multi-candidate result, and it covers quota and plan scope. For a three-parameter read tool this is nearly sufficient; only edge-case handling (no hits, ambiguous names, approximate-match tradeoffs) is missing.

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 100% and all three parameters are documented there, including the default for buscaAproximada and the UF filter example. The description adds no parameter-level detail beyond implying the name lookup, so the baseline 3 for schema-driven semantics applies.

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 a specific verb+resource ('Encontra pessoas pelo nome') and immediately states what comes back (CPF, data de nascimento, UF), so the agent knows exactly what this call produces. It names the downstream tools ficha_cpf and contatos_cpf, which differentiates it from the other lookup siblings, though it never contrasts itself with pessoas_por_endereco, the closest alternative search mode.

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?

Clear chaining guidance: 'Depois, use ficha_cpf ou contatos_cpf no CPF escolhido' tells the agent this is a discovery step feeding a detail step, which is the primary ambiguity for this family of tools. It stops short of negative guidance, e.g. when to prefer pessoas_por_endereco or what to do when the candidate list is long or empty.

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