Singapore Rainfall

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

Annotations already indicate readOnlyHint=true, destructiveHint=false, idempotentHint=true. The description adds context about the data source (NEA), station count (60), and that coordinates are included, but does not disclose additional behaviors like rate limits or data freshness. No contradiction with annotations.

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?

The description is a single sentence that is extremely concise and front-loaded with the core purpose. Every phrase adds value: data frequency, unit, source, station count, geographical scope, and license. No unnecessary words.

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?

Given low complexity, high schema coverage (100%), and presence of output schema, the description adequately covers what data is returned (mm readings, station coordinates) and licensing. It could mention that data is limited to Singapore, but overall complete for the context.

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 single parameter 'date' is fully described in the input schema with ISO 8601 format and default behavior. The description does not add any additional semantic information about parameters beyond what the schema provides, resulting in baseline score.

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 clearly states it returns 5-minute rainfall readings in mm from 60 NEA weather stations across Singapore with station coordinates. It distinctly differentiates from sibling tools like gov.sg.air_quality and gov.sg.weather_forecast by specifying the exact resource and data type.

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 description implies usage for obtaining Singapore rainfall data but does not explicitly state when to use this tool versus alternatives like weather.conditions.current or other weather tools. No when-not-to-use or alternative tool suggestions are provided.

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