Garmin Activity Heart-Rate Zones

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so basic safety is clear. The description adds only 'when available', hinting that heart-rate zones may not exist for all activities, but fails to disclose error behavior, data structure, or performance implications.

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 a single concise sentence with no extraneous words. The key information ('Get Garmin activity heart-rate zone time') is front-loaded, allowing quick understanding.

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?

Given the tool's simplicity and the presence of an output schema, the description is somewhat complete. However, it lacks context on when heart-rate zones are available, what the output contains, and how it relates to other activity tools.

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 75%, so the schema itself explains most parameters. The description refers to 'by activity id' corresponding to the required 'id' parameter, but adds no extra meaning beyond the schema.

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 'Get' and identifies the resource 'Garmin activity heart-rate zone time', making the purpose clear. It includes qualifiers 'by activity id when available' which helps distinguish it from general activity tools like garmin_get_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?

The description only states 'by activity id when available', providing minimal guidance. It does not explain when to use this tool over siblings like garmin_get_activity_splits or garmin_get_activity_details, nor does it mention prerequisites or conditions for availability.

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