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

Annotations do not include safety hints (readOnly/destructive), so the description carries the burden. It discloses that positions are live broadcasts, not schedules, which is useful, but does not cover potential rate limits, no-data cases, or other behavioral nuances.

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, efficient sentence that front-loads the core purpose ('List the aircraft') then details output. Every phrase earns its place without redundancy.

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?

Even without an output schema, the description lists the key return fields (altitude, speed, heading, distance). It is sufficiently complete for a simple list tool, though it could clarify input requirements (e.g., that lat/lon or near is needed).

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 100% and each parameter already has a meaningful description. The tool description adds little beyond the schema (e.g., mentioning 'nearest first' and 'radius in nautical miles' which are also in schema), so it adds marginal value.

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 uses a specific verb ('List') and identifies the resource ('aircraft flying near a location') with concrete output fields (altitude, speed, heading, distance). It clearly distinguishes from sibling tools like flights_track (tracking a specific flight) by emphasizing 'near a location' and 'nearest first'.

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 provides clear context (live broadcasts, not schedule) but does not explicitly state when to use this tool versus alternatives like flights_track or flights_airport. No exclusions or alternative tool names are mentioned.

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