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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety and idempotency profile is fully covered. The description adds useful context that it returns matching flights with their flight numbers and feeds into flight_quickadd, but says nothing about result volume, pagination, or empty-route behavior. Given annotations carry the behavioral load, this is adequate but not rich.

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 sentences, front-loaded with the verb and the key disambiguating condition, then the alternative in the second sentence. 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 read-only lookup with no output schema, the description supplies what an agent needs: the required inputs, the fact that it returns flight numbers, the follow-up call, and the sibling to use instead when the flight number is known. Nothing material 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 description coverage is 100%: every parameter (origin, destination, date, airline_code) already has a format hint in the schema. The description restates the same fields at a high level (origin airport, destination, local departure date, optional airline) without adding syntax or constraints beyond the schema. Baseline 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 and resource ('Find scheduled flights by route and date') and immediately scopes it with 'when the flight number is NOT known'. It distinguishes itself from the sibling flight_quickadd_lookup by naming that alternative. An agent can disambiguate from the other flight tools without opening any schema.

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 gives the when ('flight number is NOT known') and the when-not ('use flight_quickadd_lookup instead when the user already has the full flight number'). It also names the downstream step (add via flight_quickadd), completing the workflow context.

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