nearby_stops

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

Annotations already declare readOnly, idempotent and openWorld, so the safety profile is covered. The description adds that results are ordered nearest-first, which is genuine behavioral context, but says nothing about radius defaults, result limits, or truncation behavior.

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 tight sentences, scoping and ordering front-loaded with no filler. Slightly dense back-half about atcocode/towards, but nothing wasted.

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 an output schema present, return-value explanation is not required, and annotations cover safety. The gap is the undocumented `limit` parameter and the absence of any radius size guidance, leaving an agent to guess at result volume.

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 carry the load: it explains `radius` (metres) and implies the lat/lon point, but leaves `limit` (and its default of 20) completely unexplained. Partial compensation only.

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 uses a specific verb-and-resource framing ('Bus, tram and rail stops within `radius` metres of a point, nearest first') and names the ordering, which lets an agent recognize the tool distinct from nearby_stations. It stops short of explicitly contrasting itself with the 'stations' sibling, so differentiation is inferred rather than stated.

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 hints at a follow-on workflow by noting each stop has an `atcocode` for bus_departures and a `towards` direction, which implies this is the discovery step before departures. However there is no explicit when-to-use/when-not guidance and no statement of how it differs from nearby_stations or search_places.

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