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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context: it explains that the tool returns proposals with total changes, that accepted ones must be applied via swap_camino_hotel, and that proposals are chained to the new offer. This goes beyond the annotations but could still be more specific about limits (e.g., max proposals, pagination), hence 4.

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 front-loaded: the first sentence states the core function and goals. It then uses semicolons and short clauses to cover usage, fallback, and chaining. It is slightly long but every sentence carries operational information; the Spanish hint is a minor extra. No filler.

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 proposal-generation tool with an output schema, this description is exceptionally complete. It covers the trigger conditions, the goals, the optional parameter, the return contents (change in total and total if all applied), the subsequent action (apply via swap_camino_hotel), and the fallback. An agent can invoke it correctly without further research.

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 0%, so the description must compensate. It does: it lists the allowed values for `objetivo` (bajar_precio | subir_categoria | mas_centrico | con_desayuno) and explains `noche_num` as an optional limiter to one night. The third parameter, `oferta_paquete_firmada`, is not explained explicitly but its name is self-descriptive ('signed package offer'). Overall it adds meaning beyond the bare 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?

The description clearly states a specific verb-resource pair: 'Propose per-night hotel swaps on a quoted Camino de Santiago package.' It enumerates the four distinct goals (bajar_precio, subir_categoria, mas_centrico, con_desayuno) and explicitly differentiates from siblings like swap_camino_hotel (which applies changes) and quote_camino_package (which re-quotes). The purpose is unmistakable.

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 explicitly states when to use the tool ('when the client asks to LOWER THE PRICE, UPGRADE, sleep MORE CENTRAL or ADD BREAKFAST') and gives a direct exclusion ('do not re-quote'). It also routes to the sibling swap_camino_hotel for applying accepted proposals and suggests re-quoting as a fallback. This fully covers when/where/when-not.

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