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

Annotations already establish read-only, idempotent, non-destructive behavior; the description adds that this is a historical breadcrumb trail and that the id must be an fa_flight_id rather than a bare flight number. No contradictions with annotations, and the added dependency context is useful beyond the structured fields.

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 sentences carry the definition, the critical id constraint, and a runnable example; there is no filler. The most important information is front-loaded.

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 tool with no output schema, it explains the output shape (breadcrumb trail of points) and all call requirements, including the required _apiKey and the optional boolean. It could add details like time-window limits or empty-result behavior, but nothing an agent needs to make a correct first call is missing.

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%, so the baseline is 3; the description still adds value by showing how to source the required id, including a concrete example using the optional include_estimated_positions parameter. The note that a bare flight number/tail number will not work is operationally important beyond the schema's type requirement.

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 opens with a specific verb-resource pair: 'Get the historical position track' for a specific flight, and enumerates the output components (lat/lon/altitude/groundspeed points). This makes it easy to distinguish from siblings such as flightaware_flight_position or flightaware_flight_status.

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?

It gives an explicit prerequisite ('get one from flightaware_flight_status first') and an exact id format, and demonstrates invocation with a concrete example. It does not explicitly contrast with the live-position or status siblings, but the 'historical' wording plus the dependency workflow conveys when it is the right tool.

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