fitbit_get_breathing_rate

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

Discloses caching behavior (default cache, auto-sync if stale) and the live parameter. Explains return format (one entry per night, breaths_per_min) and typical adult range. With no annotations, the description fully carries the behavioral disclosure burden.

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?

Description is concise with a front-loaded purpose, a brief usage note, and clear bulleted args. Every sentence provides useful information without redundancy.

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?

Covers purpose, use case, behavior, parameter details, and return format. Mentions output structure and typical range. Output schema exists but is not needed in description due to clarity. Complete for a tool with three optional parameters.

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 has 0% description coverage, but the description provides detailed parameter info: date formats, defaults, and 'live' behavior. This adds significant meaning beyond the schema's minimal type and title.

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 clearly states 'Get nightly breathing rate (avg breaths per minute during sleep)' with a specific verb and resource. It distinguishes from sibling tools by emphasizing sleep tracking and illness/recovery signal.

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?

Provides explicit context for use as an illness/recovery signal with a concrete example (2-3 bpm increase). Does not mention when not to use or alternatives, but the sibling list provides implicit differentiation.

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