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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds two useful pieces beyond that: the response includes distance and addresses, and the operation is 'Free' (cost context). It does not cover error behavior, the 1-2000m bounds, or what happens with ambiguous input.

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 covering what is returned, followed by a one-word cost note ('Free.') that carries real signal. No filler, though the sentence is dense enough that the input/return distinction takes a second read.

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?

There is no output schema, so the description correctly summarizes the return (distance and addresses). All parameters are optional yet the tool logically needs either a cep or a lat/lon pair; the description implies this but never states it explicitly, which is the main remaining 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 all four parameters (cep, lat, lon, raio) are already fully documented with defaults and ranges. The description restates the center-point options and the radius in prose but adds no syntax or format detail beyond the schema; baseline 3 applies.

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: returns the CEPs within N meters of a point, plus the distance and addresses. It is immediately clear what the tool does, but it does not distinguish itself from close siblings such as vizinhanca or proximo, which likely also deal with nearby locations.

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?

No when-to-use or when-not-to-use guidance is given, and no alternative tool is named. The parenthetical '(a CEP, or a latitude and longitude)' clarifies accepted input forms but is not a usage rule, leaving the agent to guess how this differs from vizinhanca, proximo, or cep.

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