search_by_price_range

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

Goes well beyond the annotations by disclosing that fares come from a cache, that pricing is per adult in economy, and — importantly — that a date argument is deliberately absent because the endpoint ignores one, verified empirically, with each result carrying its own `departure_at`. It doesn't mention result ordering, staleness windows, or rate limits, so it stops short of a 5.

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?

Three short sentences with the core behavior front-loaded, followed by the usage router and then the non-obvious date caveat. Every sentence carries distinct information; no preamble or restatement of the title.

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?

An output schema exists so return formatting is unnecessary, and the description covers what an agent needs to choose and call the tool: scope, routing to siblings, the intentional absence of a date param, and the interpretation of the price bounds. Nothing material is missing for a 7-param read-only search.

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 baseline is 3, but the description adds real meaning: omitting `destination` switches the tool to an anywhere/budget-driven mode, and price bounds are framed as per-adult economy fares in the active currency. These contextualize otherwise mechanical min/max fields.

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 flights whose cached fare falls inside a minimum and maximum price'), naming the exact retrieval mechanism (cached fare) rather than a generic search. It explicitly differentiates itself from `search_flights` and `get_prices_calendar`, so an agent can pick it 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?

Gives an explicit trigger ('when the user has a budget, including anywhere under a price with no destination named'), an explicit parameter rule ('Leave destination unset to let the budget pick the city'), and names the two sibling alternatives plus the condition that selects them. Nothing is left to inference.

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