find_cheapest_dates

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely non-obvious operational behavior: the tool issues one search per day and is capped at 14 days, which tells an agent about cost/latency and a hard input boundary. It stops short of explaining round-trip semantics or what happens when trip_length_days is null.

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?

A single front-loaded sentence with the core action first and the key constraint second. No filler, no restated name or 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?

The output schema exists, so return values need no explanation, and the description covers purpose plus the 14-day limit. But for a 9-parameter tool with an optional round-trip mode (trip_length_days) that interacts with end_date, and with several undocumented parameters, the definition leaves real gaps for 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 description coverage is only 56%, and the description adds nothing beyond 'date range', which the start_date/end_date parameters already imply. Parameters such as currency, adults, and max_stops remain undocumented in both places, so the prose does not compensate for the coverage gap.

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 the cheapest day to fly within a date range'), which is clearly distinct from the sibling search_flights (specific itineraries) and find_airport (airport lookup). It does not name those siblings explicitly, so the differentiation is left to inference rather than spelled out.

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 parenthetical '(one search per day, max 14 days)' implies when the tool is appropriate and constrains the input range, but there is no explicit guidance on when to prefer this over search_flights or compare_airports. Usage is implied rather than directed.

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