download_activity_file

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

No annotations are provided, but the description fully discloses behavioral details: it saves a file to disk, overwrites existing files, supports a one-off output directory override that is not persisted, and returns a needs_setup status when no directory is configured.

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 well-structured and front-loaded, but the directory resolution and needs_setup behavior are described twice in nearly identical terms, adding minor redundancy.

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?

The description covers the key operational context and user prompting flow, but it does not describe the actual return value on success or the response schema, leaving some ambiguity about what the caller receives.

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?

Although the schema description coverage is 0%, the prose explains all three parameters: activity_id is the Garmin activity ID, format has default 'fit' and supported values, and output_dir is an optional non-persisted override.

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 clearly states the tool downloads an activity and saves it to disk as a file. It identifies the resource (activity), the action (download/save), and the output (file), which differentiates it from related tools like download_course_gpx and download_workout.

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 provides explicit guidance on when to use the tool: it explains supported formats (fit, gpx, tcx, csv), the directory resolution precedence, and the fallback needs_setup behavior with instructions to ask the user and call set_fit_download_dir.

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