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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds a genuinely useful behavioral fact beyond the annotations: the output contains no prices, so an agent knows to go to the comparison tool for cost. It does not mention result size or ordering, a minor omission.

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 short sentences with the scope front-loaded and the "no prices" caveat second. Every clause carries information and there is 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 zero-parameter, non-destructive enumeration with no output schema, the description covers what is returned (a list of insurer names) and what it is scoped to (travel offers Checko compares). It stops short of describing result shape or how the insurers relate to the coverage options returned by siblings, which leaves a small gap for an agent planning a multi-call workflow.

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 tool takes zero parameters, so there is nothing for the description to explain; baseline 4 applies. Nothing in the description contradicts or muddies the empty 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?

States a specific verb ("Lists") and resource ("Israeli insurers whose travel insurance offers Checko compares"), which an agent can distinguish from list_coverage_options and list_destinations by resource alone. No sibling is named explicitly, so differentiation is implicit rather than spelled out.

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?

"Read-only; no prices" implicitly signals this is for discovering which insurers exist, and that pricing must come from start_travel_insurance_comparison, but the description never says when to call this versus list_coverage_options or list_destinations. Usage has to be inferred from the resource name.

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