Live road traffic

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds behavior beyond that: results are sorted most-congested-first, include a count of sections per congestion level, and freeway sections follow an interchange naming convention that affects how queries must be built.

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 sentences, front-loaded with what the tool returns, then search approach, then a concrete example. Dense with useful content and no filler, though the example sentence is somewhat long.

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?

There is no output schema, and the description compensates by describing the return shape (speed/congestion values, ordering, per-level counts). It stops short of naming the exact fields, but an agent has enough to call it correctly.

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%, so baseline is 3; the description goes further by explaining the cross-parameter relationship between network and keyword/lat-lon, which the schema documents only in isolation. It also reinforces the accepted network values with an example.

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 resource (live speed and congestion of road sections) plus scope (national freeways, provincial highways, or a city's roads) and the ordering rule (most congested first). It is clearly distinguishable from siblings like traffic_events, traffic_cameras, and traffic_travel_time.

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?

Gives concrete usage context: freeway sections are named after interchanges so search by keyword, while city sections can be searched by lat/lon, with a worked example. It does not explicitly say when to prefer this over traffic_travel_time or traffic_events, but the guidance is actionable.

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