garmin_sleep

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

With no annotations, the description carries the full behavioral burden. It usefully discloses return granularity ('each night individually, not averages'), which is real behavioral context beyond the schema, but says nothing about permissions, rate limits, data availability windows, or pagination. Output schema coverage means return values need not be re-explained.

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?

Two short sentences, front-loaded with the primary capability and followed by the one distinguishing behavior (per-night granularity). No filler; every sentence carries signal.

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 documented. The description covers purpose and return granularity adequately, but leaves the two input parameters completely unspecified, which is a meaningful gap for a range-query 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 description coverage is 0% for two parameters (days, start_date), and the description never mentions either. It neither explains the default window nor the interaction between days and start_date, so it fails to compensate for the schema gap.

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 resource (sleep) and enumerates its contents (stages, SpO2, stress, Garmin feedback) with the granularity (per-night rather than averages). It is clear what the tool returns but gives no explicit differentiation from siblings like garmin_spo2, garmin_stress, or garmin_hrv, which cover overlapping metrics.

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 phrase 'for pattern analysis' implies a usage context (trend/pattern work over multiple nights), which is a weak pointer. There is no explicit when-to-use guidance and no named alternative or exclusion criteria versus the many other Garmin health tools.

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