Fitbit Weekly Health Review

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

Annotations already provide readOnlyHint, destructiveHint, idempotentHint, and openWorldHint. The description adds context about output contents (activity, sleep, etc.) and non-medical nature, but doesn't disclose behavioral traits like rate limits, data freshness, or dependency on Fitbit authentication beyond what annotations imply.

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?

The description is a single, well-structured sentence that front-loads the purpose and includes key details. Every word is purposeful, with no redundancy or fluff.

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 tool's complexity (multiple data sources) and the presence of an output schema, the description adequately covers the main return categories and constraints (weekly, read-only, non-medical). It could mention that it aggregates data across days, but this is implied by 'weekly'. Authentication requirements are assumed from sibling context.

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 high (75%), and the description adds no new meaning beyond what the schema already provides for each parameter. The tool description does not elaborate on parameters, missing an opportunity to clarify usage nuances like the 'compare_days' disabling behavior.

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 description uses a specific verb 'Build' and clearly identifies the resource as a 'weekly Fitbit scorecard' with listed components (activity, sleep, heart-rate, HRV, bottlenecks, actions). It explicitly distinguishes from the sibling tool 'fitbit_daily_summary' by specifying 'weekly', and states 'read-only and non-medical' clarifying its scope.

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?

The description implies usage for weekly analysis and notes read-only nature, but provides no explicit guidance on when to use this tool over alternatives like 'fitbit_daily_summary' or other data-specific tools. No exclusions or when-not-to-use context is given.

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