get_traffic

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful context that annotations cannot: the data is live/real-time, sourced from TomTom, and restricted to US roads, which tells the agent about staleness and coverage. It does not discuss rate limits or response shape.

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 short sentences: what it measures first, then when to use it and what to use instead. Every clause earns its place and nothing is buried.

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?

For a read-only, zero-required-parameter lookup, the description covers purpose, freshness, source, and scope, and the schema covers all parameters. It leaves the return shape vague (a speed-vs-free-flow comparison with no indication of units, per-point structure, or how an unknown road is reported), and there is no output schema to compensate. The 'place' parameter text also carries an origin/Home sentence that looks borrowed from a routing tool, a small ambiguity this description does not resolve.

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 100%, so all three parameters are fully documented in the schema, including the lat,lon formats and the 10-point cap. The description only implicitly links to points via 'each point' and adds no format or precedence detail beyond what the schema already says.

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 names a specific metric (traffic speed versus free-flow speed), the resource (the road nearest each point), and the geographic scope (anywhere in the US, TomTom). An agent can tell this apart from plan_trip and from incident or closure tools without opening the 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?

It gives a concrete decision rule, 'is the bridge backed up right now', and names the sibling to use instead for a whole drive (plan_trip). It does not mention other near neighbors such as check_route, get_incidents, or best_time_to_go, so the routing is clear but not exhaustive.

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