upload_activity

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

Annotations already establish write/open-world/non-destructive, and the description adds concrete behavior: multipart upload, plain endpoint path, no extension suffix, and no import headers. It still leaves auth requirements and response handling unstated.

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 definition is a single front-loaded sentence that earns its length by distinguishing the endpoint and header behavior from `importActivity`. It is dense with internal shorthand such as 'PLAIN' and 'load-bearing', which slightly harms readability.

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 upload tool with annotations covering safety and no output schema, the description supplies the key routing context and endpoint distinction. It could say more about authentication or expected import behavior, but the core call-completeness is present.

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 single `filePath` parameter is fully documented in the schema, so the baseline is 3. The description adds no syntax or file-type guidance beyond the schema, which already covers `.fit`, `.gpx`, and `.tcx`.

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?

It names the operation as a multipart upload and pins the exact `/upload-service/upload` path, then distinguishes it from the `importActivity` sibling by the absence of import headers. Although it relies on the tool name for the activity resource, the verb and contrast are specific enough for selection.

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?

It explicitly frames this as the ordinary device-sync-shaped upload and contrasts it with `importActivity`'s spoofed-client import, so the agent has an alternative and condition. It does not spell out broader prerequisites, but the routing guidance is clear.

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