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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive. The description adds that the tool requires no key and details what status information it provides (update times, validity, versions). This adds value beyond the annotations by clarifying the scope of the status report, though it does not describe the output format.

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 concise sentence that front-loads the tool's purpose ('Estado del servicio y de las fuentes/tablas oficiales') and then enumerates what it covers. There is no redundant information, and it efficiently communicates the essential function.

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 tool with no parameters, no output schema, and strong safety annotations, the description provides adequate context: it states what the tool reports and that no key is required. It could be more detailed about the exact response structure, but for a status check, this is acceptable. The description covers the necessary essentials.

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 schema covers 100% by being empty. Per the baseline for 0 parameters, the description doesn't need to explain parameters, and it doesn't; it simply confirms no key is needed. This is sufficient.

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 the tool reports service status and official sources/tables, enumerating what it covers (SAT list updates, tax table validity, catalog versions, rates). This distinguishes it from sibling tools like consultar_catalogo or validar_* which operate on specific data. The verb 'estado' makes the purpose explicit, though it could be more specific about the exact output.

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 implies the tool is for checking service health and data freshness but does not explicitly state when to prefer it over alternatives. It notes that no key is required, which hints at accessibility, but lacks explicit usage guidance or exclusions. Given the many sibling tools, more explicit routing would help.

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