Fitbit Weekly Health Review

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

Annotations already provide safety hints (readOnly, idempotent, non-destructive). Description adds that it is read-only and non-medical, plus lists the metrics included. This provides useful behavioral context beyond the annotations.

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?

Extremely concise: one sentence stating purpose and content, plus a short disclaimer. No filler. Front-loaded with the key phrase 'weekly Fitbit scorecard'.

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?

Given the rich annotations and existing output schema, the description covers the core functionality well. Missing mention of the comparison feature (compare_days) or response format options, but these are captured in the input schema.

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 already describes 3 out of 4 parameters (75% coverage). The description does not elaborate on parameter usage or constraints beyond what schema provides. No additional semantics added.

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?

Description explicitly states it builds a weekly scorecard with specific health metrics: activity, sleep, heart-rate, HRV availability, bottlenecks, and actions. Clearly distinguishes from sibling tools like fitbit_daily_summary (daily) and fitbit_wellness_context (general context).

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?

No guidance on when to use this tool versus alternatives. Does not mention that it provides a summary vs detailed daily data, or when to choose this over fitbit_daily_summary or fitbit_wellness_context.

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