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

Annotations only state readOnlyHint and openWorldHint; the description goes well beyond by disclosing the upstream source (adsb.lol volunteer receivers), the accuracy caveat that counts are incomplete, a refresh ceiling of 10 minutes, the status vocabulary (ok/cached/degraded/unavailable), and that nothing is estimated. It stops short of describing rate limits or per-status agent actions.

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 dense sentences, front-loaded with the data source and scope, followed by limits and freshness. Every clause conveys a distinct fact, though the parenthetical about the Airbus plant and the status list make it slightly packed for a single paragraph.

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?

With no output schema, the description must carry the return-shape burden, and it only says 'counts' and 'status' without naming the fields, groupings (airborne vs on-ground vs landings), or units. The staleness and accuracy caveats are covered well, but an agent cannot predict the response structure.

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 nothing for the description to disambiguate and the baseline 4 applies. It correctly implies the call is unfiltered and returns a fixed Hamburg-centric view.

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 the verb and resource precisely ('Open ADS-B data from adsb.lol'), and pins down spatial scope (within 100 km of Hamburg airport, plus Hamburg-Finkenwerder landings) and time window (last 24 hours). It is easily distinguished from the sibling set's generic get_sensors/get_tracks by naming the specific aircraft/landing domain.

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 implicit: an agent can infer this is the tool for Hamburg-area aircraft and Finkenwerder landing questions. However, it never states when to prefer it over get_sensors or get_places, nor does it state exclusions (e.g. no flight plans, no historical data beyond 24h).

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