List workouts

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

Annotations already establish a safe, idempotent read, and the description adds substantial context beyond them: default 7-day window, inclusive date range semantics, days ignored when start is set, pagination via next_token, oldest-first ordering, the sync-lag caveat that today's data appears only after the ring syncs, and that days without data are simply absent.

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, then usage, then parameters, then return/pagination behavior — a sensible information hierarchy. It is dense and mostly earns its length, but several clauses (date format, day limits, raw semantics) repeat what the schema already states, costing some tightness.

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 list tool with no output schema, it covers everything an agent needs: result shape ({ records, next_token }), ordering, pagination loop, default range, sync-lag and missing-day caveats, and the raw escape hatch. Nothing material is left to inference.

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 six parameters, and the description largely restates them (activity substring, days vs start, raw). It adds only marginal meaning, chiefly that start/end are inclusive and that the range defaults to the last 7 days, so the baseline 3 is appropriate rather than a higher score.

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?

Specific verb and resource (list workouts), plus scope detail: auto-detected vs manual, and the fields returned (activity type, label, intensity, source, times, duration, calories, distance). It explicitly distinguishes itself from list_daily_activity and get_heart_rate, so an agent can route 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?

Gives a concrete use case ('how many runs this month'), instructions for narrowing (activity with case-insensitive substring like 'run' or 'swim'), and names two alternatives with the exact condition that selects each — list_daily_activity for whole-day movement and get_heart_rate for in-workout heart rate.

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