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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds that the figure is an 'estimated' premium and lists the return fields, but gives no note on assumptions, rate limits, or whether the result is binding advice.

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 tight sentences, front-loaded with the purpose before the return shape and the cross-reference. The inline return-shape listing is mildly redundant given an output schema exists, but it does not bloat the definition.

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 a full schema, an output schema, and read-only annotations, the description supplies enough for correct invocation. The one missing piece is disambiguation from the sibling estimate tools, which is the main ambiguity an agent would face here.

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% and both enums are fully enumerated in the schema (destination zones, activity levels), so the schema does the heavy lifting. The description only restates the input names, adding no units, ranges, or enum semantics beyond it.

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 (Calculate) + resource (travel insurance cost) + the four driving inputs, so an agent immediately knows what it produces. It does not, however, distinguish itself from the near-identically named sibling calculate_travel_insurance_estimate (nor calculate_insurance_estimate), which is a real risk in this crowded catalog.

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?

No statement of when to choose this over calculate_travel_insurance_estimate or calculate_insurance_estimate, and no prerequisites or exclusions. The only routing hint ('See list_bundles for related voyage calculators') points to a discovery tool, not to a usage condition.

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