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

Annotations already cover the safety profile (readOnlyHint, destructiveHint false, openWorldHint). The description adds a real behavioral limit not in the annotations: it only works with future scheduled flights, which tells the agent when validation will fail. Return payload contents are also previewed.

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 front-loaded sentences: the first delivers purpose and return fields, the second delivers usage context and the scheduling constraint. No redundant or filler text.

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?

With no output schema, the description usefully enumerates the returned fields (airline name, airport, terminal, arrival time), and the date parameter is fully specified in the schema. Only minor gaps remain, such as error behavior for invalid or past flight numbers.

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 coverage is 100%, with both flight_number and date fully documented including format examples, so the schema carries the parameter semantics. The description adds no format or constraint detail beyond what the schema provides; 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?

The description states a specific verb and resource (validate a flight number) and enumerates the resulting data (airline, arrival airport, terminal, arrival time). This is unmistakably distinct from the surrounding booking-management siblings without needing to name them.

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?

It gives a concrete use case (verify a customer's flight number before booking, auto-detect the terminal) and a scope constraint (works with future scheduled flights). It does not name an alternative tool, but no sibling overlaps this function, so the guidance is effectively complete.

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