search_alternatives

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

Annotations already mark it read-only and non-destructive; the description adds behavior beyond that: results are cheapest-first, date ranges are capped at 3 days, and partial failures are surfaced in date_errors rather than failing the whole call.

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?

Every sentence adds value and the key purpose is front-loaded. The date-range cap, input format, and failure behavior are stated in just three short clauses with 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 7-parameter tool with no schema descriptions, the description leaves critical usage details unspecified: how max_results behaves, what cabin_class defaults to, and how the optional latest_departure_date interacts with departure_date. The output schema reduces the need to describe return values, but input semantics remain incomplete.

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 0%, and the description only indirectly clarifies origin/destination (IATA codes) and the date fields (at most 3-day range). It does not explain adults, cabin_class, max_results, or the exact role of latest_departure_date, leaving several parameters under-specified.

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 opens with a specific verb and resource: 'Search new one-way flights, cheapest first.' It conveys the core function, result ordering, and date-range cap, and it is not easily confused with sibling tools, which mostly concern orders, offers, changes, and bookings.

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?

The description implies the tool is for finding one-way flight alternatives and includes input constraints (3-letter IATA codes, max 3-day range), but it never explicitly says when to choose this over related tools or when not to use it.

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