oura_chronotype

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

No annotations are provided, so the description carries the behavioral transparency burden. It discloses that the tool computes an analysis rather than mutating data level. It also communicates the reference baseline (~03:30) and input source (main sleep periods), which is useful. However, it doesn't address read-only guarantees, data availability, or error conditions, so it only partially covers the 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?

A single dense sentence, front-loaded with the core action ('Computed chronotype from main sleep periods') followed by a useful list of output components. No filler or redundancy.

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?

With no output schema and no annotations, the description compensates by enumerating the computed metrics and noting a practical use case ('useful across travel'). It does not describe return format or edge-case behavior, but the tool's complexity is modest and the schema fully defines the only parameter.

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?

The sole parameter, 'days', already has high schema coverage with defaults, min, max, and description. The tool description adds no additional meaning for the parameter beyond the schema, so baseline 3 is appropriate.

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 phrase 'Computed chronotype from main sleep periods' identifies a clear verb-resource relationship and enumerates the derived metrics, distinguishing it as an analytic summary rather than raw sleep data. It doesn't explicitly name sibling tools to differentiate, but the content makes the purpose distinct from oura_sleep_periods and oura_daily.

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?

There is no explicit guidance about when to use this tool versus the sibling tools. The only contextual hint is that the day-by-day phase series is 'useful across travel', which implies a use case but doesn't state exclusions, prerequisites, or alternatives.

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