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

The description does add real context beyond the annotations: the 30-minute payment window, 24-hour observation, no L1 absolute finality, support required for late or wrong-network payments, and wallet/exchange fees. However, it is silent on what this POST itself returns and on failure semantics, and the claim that the same X-Cobranca header keeps the same charge/address sits in tension with idempotentHint=false without clarifying when a new charge is actually created.

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?

Long, run-on and poorly front-loaded: after a strong first sentence it mixes payment-finality notes, support policy, fee warnings, downstream GET/POST steps and dev-environment caveats in no clear order. Several sentences ('Each buyer pays, even when the text is ready') are ambiguous and could be dropped or rewritten.

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?

For a charge-creation tool with no output schema, it does cover timing, network and failure handling, and describes what a paid GET returns (acesso.codigo plus cookie). But it never states what this call returns (address/QR payload, expiry, status) and the vincular flow is described only vaguely, leaving the agent unable to predict the response.

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 all three parameters are already documented and the baseline is 3. The description adds only marginal meaning, namely that the token travels as X-Cobranca and should be reused across GET and retries, and that cotacao originates from GET /geracao; it does not explain the relationship between the document id and the quote.

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 opening sentence gives a specific verb and resource: it reserves an exclusive address/QR for paying with USDC on Base, i.e. it creates a charge. That is distinguishable from the sibling estado_cobranca, which only checks status. The rest of the description drifts into payment reconciliation detail, so the core purpose is stated once and then buried.

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?

Implicit prerequisites exist ('Check GET /geracao and send cotacao', the 30-minute send window), but they are embedded in prose rather than framed as when-to-use conditions. No sibling alternative is ever named (e.g. estado_cobranca for polling, consulta_comprar for pricing), so the agent must infer routing from names alone.

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