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

Annotations only say readOnlyHint=true and openWorldHint=true; the description adds that pricing follows an official table, that back-printing carries a per-piece surcharge, that freight comes from Correios with both PAC and SEDEX options, and that freight/production time only appear when CEP is supplied. It does not cover error handling for malformed CEP or whether shipping is silently omitted, so it stops short of a 5.

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 single front-loaded sentence that leads with price and appends the CEP-conditional freight clause. It is dense with comma splices but contains no filler; a slightly clearer structure would earn a 5.

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 5-parameter tool with a nested quantity object and no output schema, the description succeeds in naming the return concepts (price, PAC/SEDEX freight, production deadline) and their conditions. Only minor unknowns remain — currency, error behavior, and what exactly is returned when CEP is absent — so it is nearly complete but not fully.

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 already 80%, yet the description still adds real meaning: quantities are aggregated as a total for pricing, frente_e_verso triggers a per-piece surcharge, cep unlocks freight computation, and cor informs the production deadline. The only gap is that modelo (an enum with no schema description) remains unexplained by either source.

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?

Names the exact outputs: price from the official table for the total quantity, optional back-printing, and — when CEP is given — Correios PAC/SEDEX shipping plus production deadline. The verb 'calcular' plus these resources clearly separates it from siblings like fechar_compra or montar_link_de_compra, though it never names an alternative explicitly.

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?

Usage is only implied: an agent can infer this is the quoting tool to call before fechar_compra, and that supplying CEP adds freight. There is no explicit when-to-use/when-not statement nor any pointer to the availability or catalog tools that would supply modelo/cor inputs.

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