health_get_devices

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

With no annotations provided, the description carries the full burden, and it delivers with the key disclosure: 'Live-only (no caching) - reflects current device state.' This is critical behavioral information — the agent learns this is a live snapshot, not a cached report. The return-shape description adds further transparency, though it doesn't address error states or empty-device behavior.

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 crisp sections: (1) one-sentence purpose, (2) behavioral note with use cases, (3) return-shape enumeration. Every sentence earns its place with zero redundancy. The front-loaded headline sentence allows for quick scanning.

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 zero-parameter read tool with an output schema available, this is admirably complete — purpose, live behavior, use cases, and return fields are all covered. Could be enhanced with notes on failure modes or empty states, but those are minor for this tool's complexity.

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?

With zero parameters and 100% schema coverage (trivially satisfied), the baseline is 4. The description adds value by thoroughly documenting the output shape ('id, type, device_version, battery, battery_level (0-100), last_sync_time, mac, features'), giving the agent a full picture of what to expect from the response.

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 opens with a specific verb+resource: 'List paired devices with battery level and last sync time.' This is precise and clearly distinguishes it from siblings like health_get_activity or health_get_sleep — this is the device/resource-discovery tool. The field enumeration (battery, battery_level, last_sync_time) further cements the purpose.

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 description provides clear use-case context: 'monitoring tracker health, knowing which device produced data, and spotting sync gaps.' This tells the agent when to reach for this tool. However, it does not explicitly name alternatives or include when-not-to-use language, so it stops short of a 5.

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