fitbit_get_spo2

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

With no annotations, the description fully discloses behavioral traits: default local cache, live fetching option, dependency on sync, data sparsity, and Premium requirement. It also explains normal range and health implications, exceeding basic transparency.

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 well-structured with a clear first sentence, then bullet points and parameter details. It is moderately concise; a minor reduction in health background could tighten it slightly, but overall it is efficient.

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 moderate complexity (3 parameters, health context), the description covers purpose, behavior, parameter semantics, output format (one entry per night with avg/min/max), and prerequisites. The output schema exists, so return details are adequately supplemented.

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 0%, yet the description adds significant meaning: it specifies date formats (YYYY-MM-DD, YYYY-MM, 30d), defaults (last 30 days for start_date, today for end_date), and the boolean live parameter. This thoroughly compensates for the schema's lack of descriptions.

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 the tool retrieves nightly SpO2 data, distinguishing it from sibling tools that handle other health metrics (e.g., heart rate, sleep). The verb 'Get' and resource 'nightly SpO2 data' are specific and unambiguous.

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 explains when to use live=True vs default cache, and prerequisites (run fitbit_sync first). It notes data sparsity and Premium requirement. Although it does not explicitly contrast with alternatives, the unique SpO2 focus makes context clear.

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