import_activity

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

Annotations only cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true). The description adds genuinely useful behavior beyond that: required custom headers, and specifically that a 409 is re-raised as GarminConnectionError with a duplicate message. It stops short of covering auth/header acquisition or any return behavior.

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?

It is a single dense semicolon-chained sentence loaded with internal jargon (`NK`, `origin`, `{ext}`) and it opens with the endpoint rather than the tool's purpose. It is not bloated, but it is not front-loaded around what an agent most needs to know.

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 non-trivial import operation the description does cover mechanics and the duplicate-error path well. However, with no output schema present it should say what a successful import returns (e.g., created activity id), and it never explains how the load-bearing `NK` header is obtained, which an agent needs to actually invoke this.

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 coverage is 100% and the schema already states the file is an absolute path to a .fit/.gpx/.tcx file, so the accepted-extension constraint in the description is largely redundant. The one added nuance is that the extension is parsed out to build the URL, which is minor.

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 explains a multipart upload to a specific endpoint and notes it makes Garmin treat the file as an import rather than a device sync, so the goal is inferable. But it is framed in protocol/implementation terms rather than stating plainly that it imports a local activity file, and it never distinguishes itself from the sibling `upload_activity`.

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?

There is no when-to-use guidance and no mention of alternatives, despite a closely named sibling (`upload_activity`) whose relationship to this tool is left entirely unaddressed. The agent must guess which of the two to call.

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