garmin_sleep

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so safety is covered. The description adds the useful fact that metrics are 'available' ones (i.e., partial results are possible) but says nothing about timezone handling, missing-data behavior, or history limits. With annotations carrying safety, a 3 reflects modest added context.

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?

One front-loaded sentence with a clear verb and an enumerated payload; no filler. It is arguably a touch terse given the unaddressed 'day' semantics, but nothing is wasted.

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?

An output schema exists, so return values need not be explained, and annotations cover safety. Still missing is the one thing an agent must know to call correctly: what calendar day to pass and what happens when no sleep record exists.

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 parameter 'day' has 0% schema description coverage and the description never mentions it, so the critical ambiguity — whether 'day' means the date the sleep started or the wake-up date, and in which timezone — is unresolved. For a one-parameter tool this is the main semantic risk an agent faces.

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?

Specific verb (Read) plus resource (sleep) and an enumerated list of the metrics returned: duration, stages, score, respiration. It is clearly distinguishable from siblings like garmin_hrv or garmin_daily_metrics, though it never explicitly states the boundary with those tools.

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?

No guidance on when to choose this over garmin_daily_summary, garmin_health_snapshot or garmin_hrv, which overlap in reporting overnight data. It also doesn't state prerequisites such as wearing the device overnight or how far back data is available.

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