singapore_get_taxi_availability

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

Annotations already declare readOnly/idempotent/openWorld safety, so the bar is lower, and the description still adds real context: WGS84 coordinate system, distance-sorted radius filtering, latest-snapshot default, and that results are a bounded sample with a total match count. It doesn't mention rate limits or whether lat/long must be supplied together for radius filtering.

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?

Three tight sentences with the resource and source front-loaded, then filtering behavior, then the coordinate/return contract. No 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?

With an output schema present, return values needn't be spelled out, yet it still summarizes the bounded sample plus total count. For a 6-parameter, all-optional read tool the definition is nearly complete; only the limit/offset and coordinate-pairing semantics are left to the schema.

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 only 17%, so the description must compensate; it covers radius, date_time, and the WGS84 lat/long pair but says nothing about limit, offset, pagination defaults, or that radius_km only applies when both coordinates are given. Partial compensation earns a 3.

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 verb and resource ('Available taxi coordinates from data.gov.sg') plus scope details (radius, distance sorting). This is unmistakably distinct from siblings like singapore_get_carpark_availability or singapore_get_bus_arrivals without opening any schema.

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 'Latest unless date_time supplied' gives useful temporal context, implying when to pass a date. However, there is no explicit when-not guidance or named alternative (e.g., convert_coordinates for CRS conversion before passing lat/long), leaving usage largely implied.

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