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

Annotations already declare readOnlyHint and idempotentHint, so safety is covered. The description adds useful behavioral context by explaining that the ITP rate derives from the comunidad autónoma of the province, but it does not clarify what 'coste mínimo resultante' includes or how results are broken down, leaving the calculation's boundary fuzzy.

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, with the primary function front-loaded and the scope limitation immediately following. Every clause earns its place.

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?

With no output schema, the description should say more about what the tool actually returns — the ITP amount, the applicable rate, and what components 'coste mínimo' aggregates. It names the outputs but does not characterize them, which leaves an agent guessing at the response shape for a two-parameter calculation tool.

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 100%, and both parameters are fully documented in the schema, including that provincia determines the comunidad autónoma and ITP rate. The description largely restates that relationship rather than adding format, range or edge-case guidance beyond 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 (calculates ITP for an auction/remate value) and scopes the output to ITP plus minimum cost, explicitly excluding other expenses. It distinguishes itself from a 'calculadora completa', though that target is not among the sibling tools listed, so the routing is slightly ambiguous in this toolset.

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 second sentence gives a clear exclusion with an alternative: for registro, deudas de comunidad, cargas or reforma, go to the full calculator. However, it says nothing about when to use this versus the actual siblings (ficha_vivienda, buscar_viviendas), so cross-tool routing within the listed set is left implicit.

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