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 real value beyond that: it discloses the breadth of the dataset (which airlines), the exact attributes returned, and that limits include fare-inclusion status and a last-verified date.

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?

A single front-loaded sentence with no wasted preamble. The parenthetical airline enumeration is long but serves a purpose by signalling coverage breadth; it is the only element that pushes against full conciseness.

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?

There is no output schema, so the description must carry the return-value burden, and it does by naming the fields returned. Combined with annotations covering the safety profile, an agent has enough to call it correctly; only the exact return shape/format is left implicit.

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 the single 'market' parameter is fully documented in the schema, including its enum meanings and default behavior. The description adds nothing about market filtering, so the baseline of 3 applies.

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 ('List') and resource ('the airlines we track') and enumerates the exact fields returned (slug, IATA code, size/weight limits, fare inclusion, source, verification date). This clearly distinguishes it from siblings like check_airline_fit and get_product.

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?

Usage is implied by the content description (a reference lookup of airline baggage rules), but the description never states when to use this versus check_airline_fit, nor any prerequisites. A reader can infer the context, but there is no explicit routing guidance.

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