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

Annotations already declare readOnlyHint=true and destructiveHint=false, so 'Read-only' repeats structured data. However, the description adds real value beyond annotations: the 'newest first' ordering and the exact return-field list (number, date, customer, base, IVA, total, status, Veri*factu flag), which is important since no output schema exists.

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 sentence with the audience/scope front-loaded before the colon-delimited field list. The enumeration is slightly long, but it is warranted because no output schema exists to describe return values.

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 read-only list tool with no output schema, the description covers scope, ordering and returned fields adequately. Remaining gaps are minor: the meaning of 'accepted' client status and the default/max limit behavior (the latter is in the schema).

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 75% and already documents link_id, quarter and limit. The description adds meaning the schema does not: 'accepted' status qualifies which link_id is valid, and 'one client in a year or quarter' clarifies the mutually exclusive period filtering. The undocumented 'year' parameter is only implicitly covered by the phrase 'in a year'.

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 resource (invoices) with tight scope: 'ONE accepted client in a year or quarter', plus the exact fields returned. An agent can distinguish it from the general list_invoices by the 'gestoría account' framing and the single-client constraint, though no sibling is named explicitly.

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 'For a gestoría account' opener implies the applicable context, and 'ONE accepted client' implies usage after gestoria_listar_mandantes. But there is no explicit when-to-use/when-not guidance versus list_invoices or gestoria_gastos_mandante, leaving the choice to inference.

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