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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so 'Read-only' in the description merely restates structured data. The genuinely additive detail is that search terms may be Hebrew or English; it says nothing about result size, ordering, or pagination, which is acceptable given the annotation coverage.

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?

One sentence, front-loaded with the resource and scope, followed by the optional filter and safety hint. No filler or redundancy.

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 one-optional-parameter lookup with full annotation coverage and no output schema, the description covers purpose, filtering, and language support adequately. The only minor gap is that it does not characterize what a returned 'destination' entry contains, which matters slightly given there is no 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 coverage is 100% and the single optional parameter is already documented with examples. The description adds value beyond the schema by stating that matching works in both Hebrew and English, which the schema only hints at via a single Hebrew example.

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 ('Lists the destination regions and countries') plus the domain constraint ('that Checko's travel insurance comparison accepts'). The entity is clearly distinct from the sibling tools list_insurers, list_coverage_options, and start_travel_insurance_comparison without needing to name them.

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 word 'optionally' makes clear the query filter is not required, and '(Hebrew or English)' hints at accepted input. But there is no explicit when-to-use guidance, no mention of prerequisites, and no named alternative for the adjacent lookup tools.

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