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

Since no annotations are provided, the description carries the full burden of behavioral disclosure. It does address a critical behavioral trait: absent or empty lat/lon values are not converted to zero, and (0,0) is intentionally honored only if the user explicitly sent it. However, it omits other important behaviors such as error handling, return format, and whether the operation is read-only, leaving notable gaps.

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 three short sentences with no filler. The core purpose is front-loaded in the first sentence, and the two subsequent sentences provide critical edge-case warnings that earn their place. The structure is efficient and easy to parse.

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 simple two-parameter tool, the description covers the most important edge case (zero-coordinate semantics), but it does not mention return values or failure behavior, and there is no output schema or annotations to fill that gap. An agent would not know what the tool returns on success or how errors are signaled. Coverage is adequate for basic invocation but not complete.

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 input schema already documents both required parameters (lat and lon) with ranges, so schema coverage is 100%. The description adds meaningful semantic context beyond the schema: it clarifies the zero-coordinate behavior and warns against accidentally treating absent values as (0,0). This helps an agent handle edge cases correctly, justifying a score above the schema-covered baseline.

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 clearly identifies the tool's function: returning the closest address to a given latitude and longitude. The verb is implied ('find') but the resource ('Endereço mais próximo de latitude e longitude') and the scope are specific and unambiguous. It does not explicitly differentiate from siblings like 'raio' or 'vizinhanca', but the purpose is distinct enough that an agent can infer the intended use.

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 explicit guidance is provided on when to use this tool versus its alternatives such as 'raio' or 'vizinhanca'. The description focuses on a data edge case (the (0,0) coordinate), not on contextual decision rules. An agent must rely on the tool name and sibling names to infer appropriate usage, which is insufficient.

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