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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, covering the safety profile. The description adds the return payload keys { years, counts }, but that is also covered by the output schema, so it adds limited behavioral context beyond structured data.

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 a single, front-loaded sentence with no filler. It communicates the metric, scope, and return shape compactly.

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 aggregation tool with annotations and an output schema, the description is minimally adequate. It is missing parameter guidance and sibling differentiation, but structured fields cover safety and return details.

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 the single aircraftId parameter. It only repeats 'one aircraft id' without format, source, or examples, adding little semantic meaning beyond the parameter name and schema type.

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 metric and grouping: per-calendar-year flight counts for one aircraft id. It clearly identifies the resource and scope, but does not explicitly differentiate itself from siblings like Flight_flights_by_country or Flight_list_flights.

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?

Usage is implied by the metric description: use this when yearly flight counts for a single aircraft are needed. However, there is no explicit when-to-use, when-not-to-use, or alternative-tool guidance despite many sibling tools.

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