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

Annotations indicate readOnlyHint=false and destructiveHint=false, which is somewhat ambiguous (not read-only but not destructive). The description adds that it consumes saldo (affects balance) and that results reproduce official sources Horizons, which gives some transparency. However, it does not bias the openWorldHint or explain what actions are performed (e.g., data retrieval vs. report generation). The description does not contradict annotations, but adds minimal extra value beyond the saldo note.

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 concise, three sentences with no fluff. It front-loads the primary function, then the coverage scope, then the cost implication. It is well-organized and each sentence adds value, though the second sentence starts with 'Consume saldo' which is a bit unexpected but still relevant.

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 tool has an output schema (not provided in input but mentioned), and has 2 parameters with one required. The description covers the core purpose and financial consequence (saldo), but does not specify what the output looks like (though output schema exists) or any prerequisites (e.g., valid RFC format). It lacks mention of error scenarios or authorization needs. Given the complexity is moderate, the description is adequate but not complete—it does not mention how to handle invalid RFCs or what causes failure.

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 description coverage is 0%, meaning the schema provides no descriptions for 'rfc' or 'sancionados'. The description mentions the tool verifies by RFC and covers sancionados, but does not explain the 'sancionados' boolean parameter—its meaning is implied (whether to include sanctioned entities) but not explicitly stated. The description partially compensates for the 0% coverage by explaining the company verification context, but could be clearer about the parameters.

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 verifies a persona moral o fisica by RFC, listing specific sources (SAT 69-B, articulo 69, contratacion publica, sancionados). It distinguishes from siblings by mentioning 'sancionados' and '69-B', but does not explicitly name a sibling or differentiate from 'verificacion_completa' which might be a broader tool.

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 context that it consumes saldo and mentions a service (COMPANY) and tariff, but does not explicitly state when to use this tool versus alternatives. It does not say when not to use it or mention alternatives. The purpose is clear but usage guidance is implicit—the agent must infer it is for checking company status.

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