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

No annotations are provided, so the description carries the full burden. It correctly indicates a read-only operation via 'Get' and lists the included outputs (distance, duration, polyline), but does not disclose potential constraints, response structure, or any additional behavioral traits. For a simple read tool, this is adequate but not rich.

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, clear sentence with no filler, front-loaded with the action and key outputs. Every word earns its place, making it highly concise and well-structured.

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 straightforward 4-parameter lookup tool, the description captures the essential purpose and lists the returned data (distance, duration, polyline). With no output schema, it could benefit from a bit more detail on response format or units, but it is sufficiently complete for the tool's simplicity.

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 input schema already provides 100% coverage with clear descriptions for all four parameters (pickup/drop lat/lng). The description adds marginal semantic value by framing them as 'two points', but does not introduce new meaning beyond the schema, so the baseline of 3 applies.

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 uses the specific verb 'Get' and clearly identifies the resource as 'driving route information between two points' with explicit deliverable fields (distance, duration, polyline). This distinguishes it from sibling tools like get_fare_estimate and search_places, which serve different purposes.

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 when route information is needed, but provides no explicit guidance on when to choose this tool versus alternatives such as get_fare_estimate or get_place_details. It lacks exclusions or alternative tool references, so the usage context is only inferred.

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