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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuine value by disclosing the return shape ([{ period, count }]) and chronological sorting, which annotations do not provide. It says nothing about date bounds, timezone, or empty results.

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 compact sentences, front-loaded with the core purpose, followed by scoping and a concrete example. No filler.

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 read-only aggregation tool with an output schema already defined, the description plus annotations cover the essentials, and even restating the return shape aids selection. Missing date-format and timezone conventions are the only notable omissions.

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 0%, so the description must carry the load. It confirms the date range is optional, hints at granularity via 'day/month/year', and the WADD example shows the airport code is ICAO-style. However, dateTo/dateFrom formats and the 'hour' granularity are not addressed, so there are real 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?

States a specific verb+resource: arrival counts to one airport grouped by day/month/year. An agent can tell it returns a time series rather than a snapshot or stats, which separates it from Flight_airport_stats and Flight_airport_visits. It does not name those siblings explicitly, so it stops short of a 5.

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 example ('arrivals to Bali (WADD) for the last 12 months with granularity=month') implies when to reach for the tool, and the 'Optional date range' note clarifies scoping. But there is no when-not guidance and no comparison to the many sibling airport tools, leaving the agent to infer selection.

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