Cheapest flight per day

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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds genuinely useful context beyond that: fares are in Toman per adult, pricing is one-way domestic, and days without a flight are omitted rather than returned as nulls — a data-shape detail an agent needs. No output schema exists, so the return format is only partially characterized.

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 short sentences, zero filler: purpose and scope first, then the relationship to the sibling and the pricing/missing-day conventions. Every clause earns its place.

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 four-parameter read-only search tool with rich schema descriptions and a full annotation set, the description supplies what structured fields cannot: currency unit, one-way domestic scope, and the sparse-day convention. Minor gaps remain — whether round trips are supported and what the per-day record contains — but nothing blocks correct invocation.

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%, so origin, destination, date, and days are fully documented in the schema, including Persian/English/code formats, Jalali vs Gregorian dates, and the 1–15 range for days. The description adds only the 'per adult' currency framing and the per-day iteration semantics, which is baseline for a fully documented schema.

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 ('List the lowest domestic fare for each day') with clear scope — domestic, per-day, from a start date — and the stated goal ('pick the cheapest day to fly'). This is plainly distinguishable from the sibling al_flights, which the description names.

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 'Use before al_flights when the date is flexible,' naming the alternative and the condition that selects it. It stops short of stating the inverse (use al_flights when the date is fixed) or that international routes belong to al_flights_international, but the routing signal is strong.

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