Weight and body composition

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

Annotations already cover the safety profile, and the description adds genuinely new behavior: it reads a local cache (implying possible staleness), only days with recorded weigh-ins appear, the default window is 365 days, and the response includes period change plus an optional weight goal. A hint about needing garmin_sync first would push it higher.

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?

Three short sentences: what comes back, the recording caveat, and the default window. Field list is front-loaded and nothing is redundant.

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?

No output schema exists, so the description does its part by enumerating return fields, units, provenance, period change, and the goal. The main gap is not stating how cached data relates to freshness/sync, which matters for a cache-backed tool.

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%, so the baseline is 3, but the description adds the default 365-day window that the start_date field does not document. That is real meaning beyond the schema, though response_format and end_date behavior are left to 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?

States a specific verb and resource ('Get weigh-ins from the local cache') and enumerates the returned metrics, so an agent can tell it apart from garmin_get_daily_health or garmin_get_profile. It does not explicitly name a sibling it differs from, which holds it back from a 5.

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?

'From the local cache' and 'Only days with a weigh-in appear. Defaults to the last 365 days' imply when the data is available, but the description never says when to choose this over adjacent tools (daily health, profile) or whether a sync is needed first. Usage is only implied.

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