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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the upstream source (adsb.lol), the live/point-in-time nature that explains the idempotentHint=false, the category breakdown, and the fact that a few example aircraft are included. It does not discuss rate limits, caching, or behavior when the feed is unavailable.

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 sentence front-loads what the tool is and what it counts, with every clause (source, categories, examples) contributing information. No preamble or filler.

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, the description adequately conveys the shape of the return: per-category counts plus a few examples. The only soft spot is that it does not say what happens when the live feed is empty or unreachable, and 'a few examples' is left unquantified.

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 the baseline is 4 and there is nothing for the description to disambiguate. The description correctly implies the caller cannot narrow scope by time, airport, or aircraft type, which is the only relevant semantic point.

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 resource and scope: a live count of aircraft around Las Vegas, broken out into descending, climbing out, passing over, and helicopters, and names the data source (adsb.lol). It is unmistakable what the tool returns, though it offers no explicit contrast with the sibling tools, which happen to cover unrelated topics like hotels and events.

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 phrase 'right now' implies this is a real-time snapshot rather than a historical or forecast tool, which is the only usage cue present. There is no statement of when to prefer it, when it is not applicable (e.g. no internet or data feed outage), or what an agent should do instead for related questions.

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