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

Annotations only cover the safety profile (readOnlyHint=true, destructiveHint=false); the description adds genuinely useful behavior: the data provenance and fallback (base=indice_loqal|precos_reais with real published prices, falling back to a market reference at base=ia) and the explicit limitation that the result is an estimate rather than a commitment. That is real context beyond the structured fields.

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?

Purpose is front-loaded and the sentences are dense but purposeful – provenance, limitation, and the pre-call instruction each earn their place. It is bordering on long, but nothing is redundant.

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 carries the burden of describing the return: a split of labor/material/travel plus assumptions and open questions, and the base field explaining confidence. That is adequate, though it never clarifies how this differs from the sibling estimate_price, which is the main completeness gap.

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 3 is the baseline. The description goes slightly beyond it by supplying a worked example of what 'need' should contain ('instalar ar split de 12 mil BTUs no 7º andar, sem infraestrutura, na Tijuca') and framing 'details' as the answers that move the price, which helps the agent populate the free-text fields.

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 ('Estima quanto vai custar um serviço específico descrito pelo usuário') and even enumerates the output breakdown (mão de obra, material, deslocamento), which makes the tool's role concrete. However, it never distinguishes itself from the sibling 'estimate_price', leaving the agent to guess which estimator to pick.

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?

Gives an explicit pre-call rule – if the price-dominant detail (size, quantity, m², BTUs) is missing, ask the user first – and clarifies this is an estimate, not a budget. But there is no when-to-use vs alternatives guidance, and the obvious overlapping sibling 'estimate_price' is never addressed.

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