List sessions

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

Annotations cover the safety profile (readOnly, idempotent, non-destructive), and the description goes well beyond them: default 7-day window, days capped at 400 and ignored when start is set, days without data are absent, today's data only appears after ring sync, oldest-first ordering, and pagination via next_token. This is rich operational context that materially affects invocation.

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?

Dense but front-loaded: the core purpose leads, then routing, then range semantics, then return/pagination behavior. Every sentence carries information an agent needs, with no filler.

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 no output schema, the description specifies the return shape ({ records, next_token }), ordering, and how to continue pagination. Combined with annotations covering the safety profile, nothing needed to call this correctly is missing.

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 100%, so the schema already documents all five parameters. The description largely restates schema content (raw, days-ignored-when-start-set) but adds that start/end are inclusive, which is marginally useful. Baseline 3 is appropriate when the schema does the heavy lifting.

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 verb and resource (list mindfulness sessions in the Oura app) and enumerates the exact session subtypes and returned fields. It explicitly distinguishes itself from list_sleep_periods and list_workouts, so an agent can route correctly without opening another schema.

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?

Names the concrete use case (questions about guided practice and its effect on heart rate or HRV) and explicitly routes sleep and exercise to the sibling tools. The when-to-use and when-not-to-use conditions are both present.

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