List Authenticated Sites

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

With no annotations provided, the description carries the full disclosure burden and meets it excellently: it explicitly states the tool does NOT create a client or make an API call, and that it only inspects locally cached OAuth profiles under a specific path (~/.mercadolibre_mcp/profiles/). This removes any ambiguity about side effects or network activity without any help from 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 first sentence states the core purpose immediately, the second adds the key no-side-effect qualifier, and the final usage examples earn their place by showing the agent when to invoke it. It is slightly longer than strictly necessary, but the quoted invocation triggers add practical value for an AI caller.

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?

Since an output schema exists, the description is not required to explain return values, and it covers what, where, and side-effect profile completely. Everything an agent needs to decide to call this tool correctly is present; only minor clarity on the required empty input envelope is absent.

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 has a single required 'input' parameter that is an empty object with no properties, so there is essentially no semantic meaning to add; the description's omission of parameter details is not harmful because there is nothing to document. The description does not explicitly tell the caller to pass an empty input object, but the schema makes that self-evident.

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 names a specific resource (MercadoLibre authenticated country profiles) and a precise scope: it reports which of the 18 supported sites ARE authenticated and which are NOT. This is a concrete verb+resource statement that clearly distinguishes it from all item/order/category siblings, which are all domain CRUD operations.

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 three concrete usage example queries that define the tool's triggers ('Which countries am I authenticated in?', 'Am I set up for Uruguay yet?'). It does not name excluded alternatives, but none of the 19 siblings concern authentication, so there is no real competing tool to route away from; the examples carry the guidance.

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