list_wearable_data

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

The description discloses important behaviors beyond the read-only annotation: it explains how Zone Minutes are calculated, how calories burned may be estimated and labeled, and how TDEE is derived or why it might be missing. It also states the tool will infer defaults without asking, which is transparent.

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 verbose and somewhat repetitive: the same list of metrics appears in both the opening sentence and the 'Use when' clause. While the extra paragraphs on Zone Minutes and calories are informative, they could be condensed, and the overall length makes it harder to scan quickly.

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?

The description covers all necessary context: what data is returned, operational limits (31-day range), default handling, and special labeling for estimates. It does not describe the output schema, but that's not required for a list operation. It is complete but slightly over-explained.

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?

The schema already provides 100% coverage with clear descriptions and defaults for both parameters. The description reinforces the default behavior (INFER) but does not add new details beyond what the schema already states, though it does clarify the date format implicitly through the schema.

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 lists daily wearable data across multiple specific metrics (steps, HRV, calories, etc.), with a verb and resource. It distinguishes itself from sibling list tools like list_workouts and list_body_metrics by explicitly naming the wearable data categories.

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 includes a direct 'Use when' clause listing user queries (step count, heart rate, HRV trends, etc.) and provides operational guidance such as the 31-day maximum range and instruction to make multiple calls for longer periods. This leaves no ambiguity about when to invoke this tool.

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