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

Annotations already declare readOnly, idempotent, closed-world, so the safety profile is covered; the description adds real behavioral context beyond that: results are deduplicated per property with the lowest price, q is parsed into rule-based filters and echoes termos_entendidos, and each record carries a 4-level price label, nearest station, feature tags, and building-level counts. It does not discuss pagination limits, response size, or what happens when q parses to nothing, which is why it falls 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?

The core behavior and the q-first strategy are front-loaded, and the sentences are dense with operational detail rather than filler. The Portuguese and English halves restate largely the same content, which adds length; it is defensible for a bilingual audience but not maximally economical.

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 28-parameter tool with no output schema, the description compensates well: it enumerates what each result contains (price, R$/m², price level, station and distance, features, photo tags, building peers, both links). Combined with 100% schema coverage and read-only annotations, an agent has enough to call it and interpret the response correctly.

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 100%, so the baseline is 3; the description goes further by explaining the relationship between q and the 27 structured fields (structured fields override the natural-language parse) and by noting that the response echoes the interpreted terms. It does not resolve ambiguous interactions, such as which field wins between bairro and a neighborhood mentioned inside q, or how q combines with faixa_avaliacao.

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 description names a specific verb and resource ('Busca imóveis à venda') and bounds it tightly: São Paulo city only, sale only, deduplicated per property, with the cheapest asking price and links. Scope and exclusions are unambiguous, but no sibling tool (comparaveis_imovel, ficha_imovel, resumo_bairro, para_voce) is named or contrasted, so the agent must infer the routing itself.

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?

It states clearly when to use which input style: the easiest path is passing the user's request in q in Portuguese, and structured fields 'complete or correct' q and take precedence over it. Exclusions ('Só cidade de São Paulo; não cobre aluguel') prevent misuse. It stops short of naming which sibling to use for comparables, a single property's ficha, or neighborhood summaries.

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