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

With no annotations, the description must disclose behavior itself, but it only states the core nearest-point lookup. It does not mention output format, error behavior, coordinate range expectations, or even that this is a read-only operation. There is no contradiction with annotations, but the behavioral disclosure is minimal.

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 a single, short phrase with no wasted words, making it very concise. It is front-loaded with the key resource and operation, though it is so terse that it borders on under-specification, which prevents a perfect score.

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?

Given no annotations, no output schema, and only two bare numeric parameters, the description leaves critical gaps: return format, no-result handling, and how the query relates to the Brazilian CNEFE dataset. The presence of several geospatial sibling tools increases the need for more context than this one-liner provides.

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?

The schema provides zero description coverage for 'lat' and 'lon', so the description must compensate. It adds that these are the coordinates used to find the nearest point, which is a slight increment over the bare parameter names, but it omits important semantics such as units (decimal degrees), required range, or coordinate system.

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 phrase 'Ponto CNEFE mais perto de lat/lon' clearly identifies a spatial nearest-neighbor lookup for a specific resource (CNEFE points), distinguishing it from a generic geocoding or radius query. It is concise and not a tautology of the tool name, though it lacks a full sentence with an explicit verb like 'returns' or 'finds'.

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 gives no guidance about when to use this tool compared to the sibling tools such as 'raio', 'vizinhanca', or 'cep'. There are no alternatives named, no exclusions, and no conditions that would trigger the agent to choose this tool over another.

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