List daily activity

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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds substantial context beyond them: the 4 a.m.–4 a.m. Oura day boundary, partial today rows, missing days for no-data, sync latency before today's data appears, oldest-first ordering, and pagination via next_token. This is unusually rich behavioral disclosure.

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?

Front-loaded with purpose and scope, and every sentence carries information the agent needs. The opening field enumeration is long, but with no output schema it earns its place by telling the agent what data comes back.

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?

Even without an output schema, the description specifies the return shape ({ records, next_token }), ordering, pagination continuation, and the raw flag. Combined with the range semantics, an agent has everything needed to call and interpret it correctly.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning: end is inclusive, days is capped at 400 and ignored when start is set, and next_token should be re-passed for the rest. It stops short of adding syntax beyond the schema's YYYY-MM-DD format.

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 daily activity') and enumerates exactly what each record contains (activity score and contributors, steps, calories, distance, activity minutes, sedentary/resting/non-wear hours, alerts). It also distinguishes itself from list_workouts, so an agent can tell it apart from siblings without opening schemas.

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?

Explicitly routes usage: 'Use it for movement, step and calorie questions over a range; individual workouts are in list_workouts.' It also gives the default range (last 7 days) and the selection rule between start/end and days, leaving little to inference.

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