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

The readOnlyHint and openWorldHint annotations already indicate the tool is safe and constrained. The description adds useful behavioral context: it states that when a bairro is provided, the response includes the typical property and comparison with the city median. It does not disclose rate limits, auth, or any other operational details, but the annotation covers the safety profile. This is a moderate addition beyond annotations.

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 description is two sentences with zero redundancy. The core purpose is stated in the first sentence, and the conditional behavior for bairro is added in the second. It is front-loaded and every sentence contributes. There is no extraneous information.

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 tool with 4 parameters (1 required) and no output schema, the description explains the output (median price, and additional data when bairro is given) and the filtering dimensions. It does not describe the return format or structure, but given the simplicity of the tool, this is adequate. The absence of explicit guidance on siblings is a minor gap, but the tool's scope is clear.

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% for all parameters, including defaults for tipo and operacao. The description does not add any parameter-specific meaning beyond what the schema already provides. It mentions the dimensions (tipo, operacao, bairro) but not in a way that enhances the schema. This meets the baseline for high coverage.

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 states precisely what the tool returns: the median price per square meter for a city or neighborhood, broken down by property type and operation (sale/rental). It also mentions the additional data when a neighborhood is provided. This clearly distinguishes it from siblings like ranking_bairros or rendimento_aluguel.

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?

The description explains what the tool does but does not provide any explicit guidance on when to use it versus alternative tools. There is no mention of sibling tools or exclusion conditions. The only conditional is 'Quando o bairro é informado', which is about parameter usage, not tool selection. An agent would need to infer usage from the purpose.

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