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

Goes well past the annotations by naming the side effects ('Cria Charge EXTRA e registra atividade'), the required scope (financials:write), the risk tier, the mandatory preview+approval flow, and even that the tool is currently unavailable under this authorization. That is exactly the behavioral context annotations cannot convey.

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?

A tight, clearly segmented block: purpose first, then scope/risk/effects metadata, then availability. Dense but every clause carries operational information; the 'INDISPONÍVEL' line is unusual but not wasted.

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 destructive, approval-gated mutation with no output schema, the safety and flow context is strong, but with 6 parameters at 33% coverage the agent still lacks guidance on quantity, pricing, and when to supply an idempotency key versus an approval_id.

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 only 33%, so the description should carry parameter meaning but adds none: quantity, unit_price, description and reservation_id are never explained. The approval_id/idempotency_key semantics live only in the schema, and approval handling is only gestured at in prose.

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 concrete verb and resource ('Adiciona uma despesa adicional ... à conta da estadia') and qualifies the kind of charge ('serviço, consumo avulso'), which implicitly separates it from the sibling discount and payment tools. It never names those siblings explicitly, so differentiation is inferential rather than stated.

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?

Makes the approval precondition explicit ('Exige aprovação', 'prévia + aprovação do usuário obrigatória'), which tells the agent the expected call flow. It does not say when to prefer add_reservation_payment or add_reservation_discount instead, so the alternative-selection guidance is missing.

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