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

The description asserts 'idempotente para o mesmo dono', while the annotations declare idempotentHint=false; these directly conflict about repeat-call behavior. The ownership rule ('outro dono não pode reivindicar') is useful context, but the idempotency claim contradicts the structured metadata.

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?

Four short sentences, front-loaded with the linking action and prerequisites. The closing sentence about the code still opening the document is slightly tangential but adds behavioral context.

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?

Covers prerequisites, ownership exclusivity and post-call effect for a tool with no output schema. The main gap is the unresolved idempotency conflict with the annotations rather than missing scope.

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 100%, so both parameters are already documented. The description adds only mild meaning by framing acesso_codigo as the 'prova privada da aquisição', which is close to the schema's 'Código privado de acesso'.

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?

States a specific verb and resource: 'Vincula aquisição à conta da sessão usando a autorização privada comprada.' An agent can tell it links a purchased document to the session account, but nothing distinguishes it from near-name siblings such as documento_acesso, salvar_compra or conta_vincular_acompanhamento.

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?

Prerequisites are stated ('Exige sessão e prova privada da aquisição'), which implies when the tool is callable, but there is no explicit when-to-use vs. when-not guidance and no named alternative among the many document/compra siblings.

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