download_workout

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 does add one genuinely useful behavioral fact beyond annotations and beyond the schema: the return payload is binary FIT-file bytes, which matters for a tool with no output schema. It stops short of saying how those bytes are encoded or transferred.

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?

There is zero padding, which is good, but the content is a noun fragment rather than a sentence, so it reads as under-specification rather than disciplined brevity. The single assertion is at least front-loaded.

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 one-parameter read tool with no output schema, the description covers the single most important unknown: the return type is FIT bytes. It omits how those bytes are surfaced (base64 string, temp file, MIME type) and any size or error behavior, leaving the agent partially informed but not fully equipped.

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% for the single parameter (workoutId, 'Numeric id'), so the schema carries the parameter burden. The description adds nothing about the id, and accepts both integer and string forms without explaining that flexibility, so baseline 3 is appropriate.

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?

'FIT-file bytes' identifies the payload type, which together with the name download_workout implies fetching a workout as a FIT file. But it is a sentence fragment with no verb, and it never distinguishes this from siblings like download_activity or download_course_gpx, so an agent must infer the resource from the name alone.

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 gives no when-to-use context, no prerequisites (e.g. requires a valid workoutId already obtained via get_workouts), and no mention of alternatives such as download_activity for non-workout targets. Three words of fragments leave all routing to inference.

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