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

With readOnlyHint, destructiveHint=false, and openWorldHint=false already provided, the description adds meaningful context by describing the return shape ([{ period, byCountry: {...} }]) and that results are sorted chronologically. It does not cover auth or rate limits, but for a read-only query this is solid additional detail.

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?

The description is front-loaded with purpose, then return structure, then a concrete example. Every sentence earns its place without waste, making it easy to parse quickly.

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 the return value explanation is redundant but not harmful. For a tool with five parameters and zero schema descriptions, the description leaves important parameter details (granularity, date format, code patterns) unaddressed, making it only partially complete.

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%, so the description must compensate for all five parameters. It mentions the optional date range and country filter, and the example shows the country array format, but it omits any explanation of granularity (enum with default), date format, airport code pattern (4 uppercase letters), or country code pattern (2 uppercase letters). This leaves significant gaps.

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 states a specific verb+resource — arrival counts to one airport broken down by departure country — and clarifies the grouping dimensions (day/month/year). It does not explicitly differentiate itself from siblings like Flight_airport_arrival_trend or Flight_flights_by_country, but the purpose is otherwise clear.

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 usage via the example (comparing India vs China arrivals to Bali) and notes optional date range and country filter. However, it offers no explicit when-to-use versus when-not-to-use guidance or named alternatives among sibling tools.

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