get_sleep

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

Annotations already cover read-only, idempotent, non-destructive, open-world behavior, so the description's added value is the 31-day range ceiling, the end_date default, and the caveat that Garmin calendarDate is preserved while wake-date vs sleep-start-date association needs live verification. That is meaningful operational context an agent cannot get from structured fields. It does not mention failure behavior when the range is exceeded.

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 what is returned, then the range/default rules, then the calendarDate caveat — no filler. The final sentence is dense and slightly cryptic, but it is one line of real content rather than padding.

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 spelled out, and the description covers range limits, defaults, and the date-association ambiguity. What is missing is error behavior past 31 days and any timezone note, which matters for a date-scoped sleep query.

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 0%, so the description must carry the parameters, and it does: dates are inclusive ISO dates, the range is capped at 31 days, and end_date defaults to start_date. The semantics of both parameters are clarified beyond the bare pattern in 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 states concretely what is returned: sleep duration/stages in seconds, score components, and window times. That is far more specific than the name alone, though it never explicitly distinguishes this from get_daily_summary, which likely overlaps on sleep content.

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?

It gives a hard constraint (inclusive range of at most 31 days, end defaults to start) but no guidance on when to call this instead of get_daily_summary, get_hrv, or other siblings, and no exclusion conditions. The agent must infer the selection rule from sibling names.

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