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

With no annotations, the description carries the full behavioral burden and does not meet it. It discloses provenance ('tracked by FerryFlight') and that data is live/ADS-B, but says nothing about freshness windows, result volume, pagination, rate limits, or whether the snapshot is cached, all of which matter for a zero-parameter live-data endpoint.

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?

A single efficient sentence with no redundant wording or filler. Brevity is not the problem; the sentence simply omits information an agent needs rather than padding.

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 zero-parameter tool with no output schema and no annotations, the description is the only place an agent can learn what comes back. It omits return shape, time window, and result size, leaving the agent unable to predict the response before calling.

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?

The tool takes zero parameters, so there is no parameter meaning for the description to add. Baseline 4 applies; nothing here misleads about inputs.

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 names a specific resource (live ADS-B flights tracked by FerryFlight), which distinguishes it from lookup siblings like get_aircraft and get_airport. But it is a noun phrase with no verb, and 'Recently observed' gives no indication of whether this returns a list, a count, or a single flight, nor what 'recently' means.

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?

There is no guidance on when to use this tool versus the other nine siblings, no prerequisites, and no exclusions. An agent cannot tell from the description whether to call this before or instead of get_aircraft, get_route, or the search_* tools.

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