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

Annotations already declare readOnlyHint, openWorldHint=false and idempotentHint=true, so the safety profile is covered. The description adds useful output context (returns a valid example JSON plus a link to the guide), but with no output schema it does not describe the JSON structure or any size/rate constraints.

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?

A single, front-loaded sentence that states the return value first and enumerates the codes compactly. No wasted words, though the parenthetical code list makes it slightly dense.

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 one-parameter, read-only example generator with 100% schema coverage, the description tells the agent what it produces (sample JSON) and that a guide link comes with it. Adequate, though it could say a bit more about what the returned example contains.

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 100% and the single parameter is fully documented in the schema, so the baseline is 3. The description restates the code list with the human-readable names, which mirrors rather than extends the schema.

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 and resource: it returns an example JSON valid for issuing a voucher type, enumerating the supported codes (01 factura ... 07 retencion). This clearly separates it from sibling documentation tools, but it never explicitly names an alternative, so differentiation is implicit rather than stated.

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?

Usage is implied by the output (you call it when you need a sample payload for a given voucher type). There is no explicit when-to-use, when-not, or routing to siblings such as leer_guia or consultar_referencia, which is a clear gap in a cluster of documentation tools.

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