Singapore PM2.5 Air Quality

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

Annotations (readOnlyHint, idempotentHint) already indicate safe read operation. Description adds behavioral context: data source ('NEA, SG Open Data Licence v1.0') and real-time/historical distinction, which provides transparency beyond annotations. No contradictions.

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 sentences: first states purpose and scope, second covers parameter usage and data source. No wasted words, front-loading core purpose. Ideal conciseness.

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?

Covers purpose, parameter, data source, and license. Output schema exists, so return format info is not needed. Could mention update frequency for 'real-time' but otherwise complete for a simple read-only tool.

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 coverage is 100% with a clear description for the single parameter. Description merely restates schema info (optional date for historical data, omit for latest). While accurate, it adds no new meaning beyond the schema.

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?

Description clearly states 'Real-time PM2.5 readings (μg/m³) for the 5 Singapore regions' - specific verb (readings implicitly get), resource (air quality), and scope (5 regions). Sibling tools (rainfall, taxi_availability, weather_forecast) are distinct, so no ambiguity.

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?

Description explains when to use: for current snapshot or historical data via optional date parameter. It does not explicitly mention when not to use or alternatives, but given sibling tools are unrelated, this is clear enough for an agent.

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