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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so safety is covered. The description adds genuine behavioral context beyond that: it returns null when the id is missing and it is a lightweight header-only read rather than the derived-stats path. It stops short of describing error/auth behavior, so not a full 5.

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 short sentences with zero filler, front-loading the scope and null-return behavior before the sibling referral. Every clause earns its place.

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 return-value detail is not required, and the description still adds the null-on-miss case. For such a simple one-parameter read, the definition is essentially complete, with only marginal room for auth or rate-limit notes.

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 carries the burden, and it does note the lookup is 'by id'. However, the single parameter (aircraftId, string) is self-describing and no format, prefix, or case constraints are given, so it only marginally exceeds what the schema already conveys.

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 ('Single AircraftList row by id') and immediately scopes it as a 'fast header lookup,' which cleanly separates it from the heavier sibling Flight_get_aircraft_detail. An agent can pick between the two without opening either schema.

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?

Explicitly routes the agent: use this for the fast header lookup, use get_aircraft_detail for charts and full derived stats. The when-to-use-this and when-to-use-alternative conditions are both stated.

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