get_resting_heart_rate

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

With no annotations, the description carries the behavioral disclosure burden. It does reveal that the tool returns historical data over a time range and specifies the end-date format, but it omits details like optionality of end, default behavior, inclusivity of endpoints, or timezone handling. These are lower-stakes omissions for a read-only get tool, but still leave gaps.

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 compact sentence with no filler or redundant restatement of the tool name. It front-loads the resource and immediately communicates the time-window semantics, so every part earns its place.

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 tool is simple—two optional parameters, no nesting, and an output schema—so the description covers the essential selection logic. However, the lack of explicit routing guidance matters in a large sibling family of health-metric tools, and the description does not fully compensate for the absent annotations.

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 0%, so the description must explain the parameters, and it does: 'N' maps to days and 'end' is identified as a YYYY-MM-DD date. This adds real meaning beyond the bare schema types, though it does not explain null/default 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 identifies a specific resource ('Resting heart rate history') and a clear time-window scope ('last N days'), which helps distinguish it from sibling tools like get_daily_heart_rate and get_hrv. It lacks an explicit verb but the tool name and noun phrase convey the intended retrieval clearly.

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 a use case—retrieving resting heart rate history over a trailing window—but it does not explicitly state when to prefer this tool over related alternatives. No exclusions or alternative tool references are provided, leaving some routing inference to the agent.

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