download_activity_gpx

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

With no annotations available, the description carries the behavioral disclosure burden. It clearly discloses two key behaviors: the tool saves the GPX track file to disk and returns the file path rather than raw file content. This is valuable and goes beyond the tool name, though it does not cover error cases or permissions.

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 concise sentences, each serving a distinct purpose: the main action, the side-effect return behavior, and the use-case context. The description is front-loaded with the core action and contains no filler.

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 simple single-parameter download tool, the description covers the essential elements: purpose, save behavior, return value, and use case. It is slightly incomplete because it does not mention how to obtain a valid activity_id or address activities without GPS data, but these are minor gaps given the output schema exists.

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 0%, so the description must compensate for parameter guidance. It mentions 'a specific activity' but never explains how to supply activity_id, what values are valid, or where the ID can be obtained. The parameter name alone is not sufficient for reliable invocation.

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 a specific verb ('Download') and resource ('GPX file for a specific activity'), immediately identifying what the tool does. The mention of GPS coordinates and mapping helps distinguish it from the sibling format downloaders (FIT, TCX, KML, CSV).

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 statement 'GPX files contain GPS coordinates and are useful for mapping' provides implied guidance on when to choose this tool. However, it does not explicitly name alternatives such as download_activity_fit or download_activity_tcx, nor does it state when NOT to use this tool.

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