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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true. The description adds meaningful behavioral details: no unit prices are provided, preseleccionado marks defaults based on nationality, IDs are not shown (from the Spanish 'sin mostrar IDs'), and these are the only allowed extras. This goes well beyond the annotations without contradicting them.

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 dense and information-packed, covering the core purpose, content types, pricing behavior, preselection logic, and exclusivity. It includes both English and Spanish text, but this is not redundant given the tool's context. Every sentence adds value, and the key constraint (only extras allowed) is prominent, making it appropriately sized without excessive verbosity.

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 an output schema present, the description need not enumerate return fields. It fully covers the catalog's scope, the absence of unit prices and IDs, the preselection semantics tied to nationality, and the exclusivity of these extras. An agent has sufficient information to invoke the tool correctly and interpret its output in context.

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?

The schema's 'nacionalidad' parameter has no description (0% coverage). The description indirectly explains its influence by stating 'preseleccionado marks the defaults (credential + insurance by nationality)', implying the parameter filters which extras are preselected. However, it doesn't explicitly state that the parameter is optional or how it affects the result set, leaving room for interpretation.

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 this is the official catalog of pilgrim extras for the Camino de Santiago, enumerates the categories (credential, insurance, luggage transfer, etc.), and explicitly notes it is the ONLY extras that may be offered. This fully distinguishes its purpose from any sibling tool such as list_camino_routes or quote_camino_package.

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 implies usage by stating that pricing is folded into quote_camino_package and that no unit prices are shown here, which hints that pricing-related queries belong elsewhere. However, it does not explicitly state when to use this catalog versus alternatives, nor does it provide when-not-to-use rules. The 'only extras' clause is helpful but lacks direct routing.

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