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

readOnlyHint=true already establishes this as a safe, non-mutating calculation, and the description usefully discloses what the computation covers (SS, IRPF/IS, dividends) plus that it returns a recommendation and threshold. It does not state assumptions (tax year, jurisdiction defaults) or caveats, which is acceptable given the annotation.

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?

Two sentences, zero filler. The scope and factor breakdown come first, the output (recommendation + threshold) second, making it well front-loaded.

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 comparison calculator with fully documented parameters and a clear output statement, the definition is nearly self-sufficient. Minor gap: no note on assumptions such as applicable tax year or regional variation, which could affect interpretation of the result.

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%, with enums and defaults fully documented in the schema itself (regimen, tipo_is, beneficio_anual, gastos_deducibles, repartir_dividendos). The description adds nothing beyond that, so the baseline 3 for full schema coverage applies.

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?

Specific verb (compara) plus a precisely bounded resource: total tax burden (SS + IRPF/IS + dividendos) of operating as autónomo vs forming an SL. It even states the output intent (which is better and the threshold), and the autónomo-vs-SL framing is naturally distinct from siblings like comparar_modulos_vs_directa.

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 scenario is implied by the comparison itself, but there is no explicit when-to-use, prerequisites, or routing against alternatives such as comparar_modulos_vs_directa or calcular_cuota_autonomo. Usage is inferable rather than stated.

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