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

With no annotations, the description carries the full behavioral burden and it covers only part of it: it discloses the return fields, nearest-first ordering and a cost of 10 credits, which is genuinely useful. It says nothing about how fresh/live the data is, whether results are capped by the radius maximum, failure modes for out-of-range coordinates, or auth requirements — significant omissions for a tool with zero structured hints.

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 front-loaded sentence that leads with the resource and scope, then the ordering, then the payload fields and cost. It is efficient, though the trailing field enumeration makes it a long run-on rather than a crisply structured statement.

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 read-only spatial query with no output schema and four undocumented parameters, the definition covers return fields, ordering and credit cost but omits result-count semantics (limit) and data freshness. Barely adequate for the tool's complexity; it needs one or two more clauses to be complete.

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 description coverage is 0%, so the description must compensate and only partly does: it names radius_km and establishes the lat/lon pair, but never mentions the limit parameter (default 50, max 200), nor the defaults and ceilings on radius_km (50/300). An agent would not learn from the description that the result count is controllable at all.

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 pairs a specific resource with a precise scope: 'Aircraft currently airborne within radius_km of a latitude/longitude', and adds ordering ('nearest first') and returned fields. That is enough to distinguish it from a broader flight-lookup tool, though it never names or contrasts a sibling such as aircraft_overhead or aircraft_track, so the differentiation must be inferred.

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 implies usage through the phrase 'currently airborne' (i.e., real-time position queries rather than historical ones), but there is no explicit when-to-use, when-not-to-use, or alternative-selection guidance. Given several sibling tools cover aircraft near/overhead concepts, the absence of routing guidance leaves the agent to guess.

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