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

Annotations already establish that this is a safe, idempotent, read-only, closed-world query. The description goes beyond that by disclosing pagination behavior ('pass next_cursor to get the next page') and the exact shape of returned records, which annotations cannot express.

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?

Two tightly written sentences: the first front-loads what the tool returns, the second covers pagination and the field list. No filler, and the return-value detail is justified since no output schema exists.

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?

With no output schema, the explicit field list (month, passengers, domestic, international, movements) and pagination note fill the main gaps an agent would hit. It does not explain units or how the month / month_gte / month_lte filters interact, but those remain readable from the schema.

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 every parameter is already documented as a baseline 3. The description adds nothing about filter semantics and, if anything, risks confusion by naming 'next_cursor' when the actual parameter is 'cursor'.

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 resource (air passengers in Sweden) with an explicit granularity (per month), which is clear and unambiguous. It does not, however, distinguish itself from the nearby sibling airport_passengers, which an agent could plausibly confuse with a nearly identical-sounding dataset.

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 gives no when-to-use guidance, no prerequisites, and no mention of the adjacent sibling airport_passengers that covers similar-sounding data. The only clue is the resource name itself, so the agent must infer everything about selection.

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