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

Annotations already mark the tool readOnly, idempotent, and non-destructive, so the bar for added value is lower. The description exceeds it by disclosing that it stores nothing, submits nothing, relies on dated official sources, and is not legal advice — all meaningful behavioral context beyond the annotations.

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 front-loaded with the trigger condition and then packs in the output contents, limitations, data-handling guarantees, and claim route without wasted words. Every clause contributes useful routing or behavioral information.

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?

Despite having no output schema, the description spells out what the response contains: verdict, rule, amount, current airline obligations, facts that could change the outcome, claim path, and evidence. Combined with 100% schema coverage on inputs, an agent has everything needed to call it correctly.

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 schema already documents every parameter fully. The description reinforces some domain concepts, like overbooking and downgrades, but does not add significant semantic detail beyond what the input schema provides. 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 action — checking EU261/UK261 compensation eligibility — and names the triggering events (cancelled, delayed, overbooked, downgraded). It clearly distinguishes the domain (flights only, not ferries) and gives a concrete sense of the result (verdict, rule, amount, claim path).

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?

Explicitly says when to use the tool: when a traveler's flight was disrupted and they ask what they are owed or their options. It also provides a clear exclusion ('Flights only, not ferries') and outlines the claim process, making the intended call context unambiguous.

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