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

With no annotations, the description takes on the full burden. It discloses the core behavior (format and Luhn digit validation) and a key limitation (no IMSS affiliation check), but does not mention output response, error behavior, or any side effects. For a read-only validation this is adequate but not thorough.

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?

Three short sentences with the main purpose front-loaded. The second sentence, 'Incluido con saldo de paquete', adds a billing context that is not directly relevant to invocation, but overall the description is tight.

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 single-parameter validation tool with no annotations and no output schema, the description covers purpose and limitation but omits the expected input format and return value. It is minimally viable but leaves the agent uncertain about output and exact input syntax.

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?

Schema coverage is 0%, so the description must compensate. It expands the abbreviation 'NSS' to 'numero de seguro social', but does not specify the expected format, length, or examples beyond mentioning a Luhn digit. The agent must guess the input shape.

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?

States a specific verb (Valida), resource (NSS), and exact checks (formato y digito Luhn). The tool is clearly distinguishable from sibling validators like validar_curp or validar_rfc because it names NSS and its specific algorithm.

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 includes one explicit exclusion: 'No confirma afiliacion ante el IMSS', which tells the agent when not to use it. However, it does not name alternative tools for affiliation confirmation nor describe positive scenarios for selecting this tool over siblings.

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