Get User

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

With no annotations provided, the description carries the burden of behavioral disclosure. It implies a read-only operation by saying 'get' and mentions 'authenticated user' and 'public profile', suggesting authentication requirements. Yet it does not explicitly state that it makes no modifications, what happens on missing authentication, or any rate limits. The description conveys the core behavior but leaves out some transparency that a robust agent would benefit from.

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 two short paragraphs: one states the core purpose and the empty-user_id behavior, the other gives two on-target examples. Every sentence earns its place, no fluff, and the most important detail (the empty-user_id behavior) is front-loaded. This is exemplary conciseness.

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?

The output schema already documents the return structure, so the description does not need to duplicate that. The description covers the two primary modes (own profile vs. specific user) and provides clear examples. It could mention that 'account' is optional, but the schema already does, and the context is sufficiently complete for a get-unified read tool. Minor extra context like error handling would be nice, but not necessary given the schema and examples.

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 description significantly adds meaning to the user_id parameter by explaining that leaving it empty returns the authenticated user's profile, which is not obvious from the schema alone. The examples also clarify the site_id argument (e.g., 'MLA' for Argentina). The account parameter is not described, but the schema handles it. Given that the schema descriptions are already present, the description's added semantic value is meaningful.

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 opens with a specific verb and resource: 'Get public profile and seller reputation for a MercadoLibre user.' It unambiguously states what the tool does and is clearly distinct from the sibling tools, which all deal with items, orders, or similar domains. This fully clarifies purpose with no ambiguity.

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 provides two concrete usage examples that illustrate when to call the tool (e.g., fetching one's own profile vs. another user's reputation). It also explains the behavior of leaving user_id empty, which is a critical usage rule. However, it doesn't explicitly contrast with alternative tools, but the resource distinction is strong enough that an agent can infer when this tool applies.

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