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

Annotations already cover read-only, idempotent, non-destructive, so the description isn't burdened with safety disclosure. It adds that results link to specific flights for viewing and enquiry, which is useful behavioral context about how to proceed after results. No contradictions.

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?

Three tight sentences with front-loaded purpose, explicit usage trigger, and result behavior. No fluff or repetition.

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 search tool with full schema coverage and an output schema, the description covers the purpose, usage context, filter options, and post-result behavior. Nothing essential is missing.

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 covers all four parameters with descriptions, matching the description's mention of origin, destination, and region filters. The description adds no new semantics beyond the schema, so baseline 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?

States a specific verb and resource ('Search Villiers' available empty-leg flights') with context on what empty-leg flights are. Clearly distinguishes from sibling tools by being the search/listing tool while siblings handle status, estimates, and requests.

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 guidance: 'when a user wants cheap private jet deals, is flexible on dates, or asks about discounted or empty-leg flights.' Doesn't explicitly name alternatives, but sibling tools are distinct, and the description implies this is the search entry point. Could have added exclusions, but adequate.

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