Get sleep (one night)

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds genuine behavioral context beyond that: the exact fields returned, that durations are in seconds, and the night-boundary semantics. It stops short of noting data availability caveats (e.g., watch not worn) or how missing metrics appear, which keeps it from a 5.

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?

Front-loaded with verb, resource and scope; the alternative is placed at the end where it belongs. The long field enumeration is lengthy but each item is a returned metric, which is load-bearing information given there is no output schema.

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 read tool with no output schema, the description covers the date semantics, units, and a near-complete inventory of return fields, plus sibling routing. A minor gap is the absence of any note about sparse or unavailable data on nights the device wasn't worn.

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% for the single `date` parameter, so baseline would be 3. The description earns above baseline by restating the semantic interpretation ('the night ending on that morning') that the schema phrase 'date of the morning you woke up' could otherwise be misread.

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 sleep data for one calendar date') and immediately disambiguates the time window with 'the night ending on that morning.' It also names the sibling that handles the multi-night case, so an agent can distinguish it from garmin_get_sleep_summaries without reading either schema.

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?

Explicitly routes the agent: single night here, 'For several nights use garmin_get_sleep_summaries.' The parenthetical about which night the date refers to removes the most likely usage mistake (off-by-one-night).

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