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

Annotations already cover read-only and open-world behavior, lowering the burden on the description. The description adds valuable behavioral context by stating the output is a calendar view of minimum prices, which is especially important since there is no output schema. It does not mention data freshness or empty-result handling, but those are minor for a safe read-only tool.

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?

Both sentences are short and purposeful: the first states the core action and resource, and the second adds the differentiating output format. There is no filler or repetition.

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 simple read-only search with only five well-documented parameters, this definition is largely complete. The only notable gap is direct guidance about when to prefer this over sibling tools like search_flights, but the 'flexible date travelers' phrasing partially covers that.

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 100%, so the schema fully documents origin, destination, targetDate, daysBefore, and daysAfter. The description does not add parameter-level detail, but it does not need to because the schema already carries that burden.

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 uses a specific verb ('Find') and a specific resource ('cheapest travel dates around a target date'). The phrase 'calendar view' clearly distinguishes it from standard flight price search tools, and the flexible-traveler framing reinforces its purpose.

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 states it is for 'flexible date travelers', which gives clear context for when it should be used. It does not explicitly name alternatives such as search_flights or state when not to use this tool, so it stops short of a 5.

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