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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds that this is a composite operation over the live catalog and built-in country references, which is useful behavioral context beyond the annotations, though it does not add authentication or rate-limit details.

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 two tight sentences. It front-loads the usage condition and then efficiently specifies the composite output and data sources, with no redundant or filler content.

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?

Given the rich annotations, full schema coverage, and an output schema, the description supplies everything an agent needs: when to call it, that it is a composite read-only operation, and what the single-call answer includes. Return-value details are appropriately deferred to the output 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 description coverage is 100%, so the schema already documents countries, days, and usage_profile. The description restates the itinerary inputs as countries + days + usage but adds no syntax, ordering, or enum guidance beyond what the schema provides, so the baseline of 3 is appropriate.

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 states a specific composite purpose: it produces an estimated data need, a best plan pick with an alternative, and a per-country networks/eSIM/freedom brief in one call. It distinguished itself from sibling tools such as recommend_plan and calculate_data_budget by explicitly framing itself as a composite over the live catalog and built-in country references.

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?

It gives a clear condition for use: when the user provides an itinerary of countries, days, and usage, and wants the full answer in one call. It implies that single-purpose sibling tools are the alternative when only one component is needed, but it does not name those alternatives explicitly.

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