health_get_skin_temperature

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

Since no annotations are provided, the description carries the full burden of behavioral disclosure. It clearly explains the key caveat that this is a relative deviation (can be negative), not an absolute temperature, and mentions the live parameter's re-fetch behavior. It doesn't explicitly state that this is a read-only operation, but that's implied by 'Get...' and the general tone. One minor gap is a lack of error conditions or permission requirements.

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?

The description is efficient and front-loaded: the first sentence states the core purpose, followed by critical context (what it is NOT), usage guidance, and clear Args section. Every sentence adds value; there is no fluff or redundant content.

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?

Despite having a simple schema (3 parameters, all optional) and an output schema, the description provides all essential context for a health metric tool: what the data represents, units, baseline caveat, use cases, and parameter formats. The output schema covers the return structure, so the description doesn't need to dwell on it. For a tool without annotations, this is comprehensive.

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?

Although schema description coverage is 0%, the description provides detailed meaning for all three parameters: start_date and end_date formats (including shorthand like '30d' and defaults), and the live parameter's behavior. This fully compensates for the schema's lack of descriptive text, adding practical examples and default values not obvious from the schema alone.

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 starts with a specific verb+resource ('Get nightly skin temperature variation') and clearly distinguishes it from the sibling tool health_get_core_temperature by explicitly stating it is a relative deviation, not absolute body temperature. This differentiates it from the many sibling health_get_* 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?

The description explicitly tells when to use this tool (for illness/cycle/recovery signals) and when NOT to use it (for fever/body-temperature readings, use health_get_core_temperature instead). It also mentions the three-night baseline establishment period, which is a critical prerequisite for understanding why data might not appear.

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