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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds behavioral context beyond annotations, such as rendering the comparison widget and instructing the agent to reply with 1-2 sentences highlighting the recommended offer. This provides helpful extra transparency about side effects and response expectations.

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 three sentences, front-loaded with purpose and usage, then post-call instructions. Every sentence earns its place; no redundant 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?

The tool has a complex nested schema, no output schema, and full parameter descriptions in the schema. The description explains the output at a high level ('priced offers' and 'comparison widget') and provides necessary agent behavior for call success. It does not detail the return structure, but given the schema's thoroughness, this is a minor gap.

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 baseline is 3. The description adds meaningful guidance: it identifies the truly required fields (countryResidence, arrivalCountries, traveller ages) and establishes a policy that optional fields have sensible defaults and should never be asked for. This goes beyond the schema's individual field descriptions.

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 'Use this whenever the user wants travel-insurance quotes' and specifies what it does: 'Returns priced offers from HelloSafe partners and renders the comparison widget.' This is a specific verb+resource purpose, distinguishing the tool even without sibling context.

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?

Provides explicit when-to-use ('whenever the user wants travel-insurance quotes'), required fields, and clear exclusions: 'never ask the user for an optional field' and 'never re-list offers as a table, never paste subscribe URLs.' No alternatives exist, but the 'when not to' is implicitly handled by 'required' and optional policy.

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