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

Annotations already declare readOnlyHint=true and openWorldHint=true, indicating safe, read-only access. The description adds that the tool returns sections and pages with URLs, which is a concrete behavioral expectation. It does not contradict annotations and provides clear content expectations, though it does not specify output format (e.g., list vs. tree). Given zero parameters and annotations covering the safety profile, this is adequate.

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, well-structured sentence that front-loads the tool's core content ('El menú de cambio-uruguay.com') and immediately states what it provides. No filler words, every phrase contributes to understanding.

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 zero-parameter tool with no output schema, the description sufficiently explains what the tool returns (sections and pages with URLs) and its purpose (orientation). It lacks explicit details on the response format or structure, but given the simplicity and annotations, it is nearly complete. A slightly more explicit statement about the returned data structure (e.g., 'returns a list of sections and pages') would push it to 5.

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 tool has zero parameters, so the description needs to explain none. The baseline for 0 params is 4, and the description adds no parameter-related information, which is appropriate. There is nothing to compensate for.

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 states that the tool returns the site's main sections and pages with URLs, acting as a menu for cambio-uruguay.com. It uses a specific verb ('menú' implies providing a list) and a resource, distinguishing it from search-oriented siblings like search_site or read_page.

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 mentions the purpose is 'to orient the person about what is on the site and where,' which implies use for navigation or overview. However, it does not explicitly mention when to use this tool over alternatives like search_site or list_directories, nor does it give exclusion criteria. The guidance is implicit rather than explicit.

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