apple_maps_eta

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

The description clearly enumerates the output fields (live best estimate, historic and free-flow durations, distance) and calls out the no-cycling limitation. It fails to mention any error modes or response format, but the core behavior is well-disclosed given no annotations exist.

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 compact yet complete, front-loading the purposehare then returning quickly to parameter context. It avoids redundant filler and covers all essential facts. Slight inefficiency in repeating 'between two points' twice, but otherwise 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?

Given that no annotations, output schema, or additional context are provided, the description independently conveys what the tool does, its return payload, when to prefer it over the directions endpoint, and a notable data limitation (no cycling). Parameter semantics are clarified in the schema. This is thorough enough for an agent to select and invoke the tool appropriately.

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 four coordinate parameters are self-explanatory and documented. The 'mode' and 'country' parameters lack explicit value sets ('walking', 'driving'; country code meaning). The description fills some semantic gaps by noting cycling absence and default driving, and the schema descriptions provide baseline coverage, but not full clarity on allowed values.

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 very first sentence states exactly what the tool does: 'Get Apple Maps travel-time estimates between two points'. It then details what estimates are returned for each transport mode, which fully disambiguates its purpose from a general maps or directions tool.

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 mentions when to use it ('Cheaper than the directions endpoint when only the time and distance are needed') and when not to use it for cycling. However, it doesn't give explicit guidance for scenarios like walking vs. driving trade-offs or mention that the country parameter might be needed. It could better help the model choose between this and the directions endpoint based on parsing requirements.

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