heart_rate_day

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

With no annotations, the description carries the full behavioral burden. It mentions return contents and the timeseries condition, but does not state read-only behavior, date/default handling, timezone assumptions, error behavior, or output shape.

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 definition is a single compact sentence with no wasted text, and the key conditional behavior is front-loaded in the parenthetical.

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?

For a tool with two undocumented parameters, no annotations, and no output schema, the description is too sparse. It covers the main purpose and one parameter condition but leaves date semantics, safety profile, and return structure insufficiently specified.

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% for both parameters. The description explains include_timeseries semantics, which is valuable, but the date parameter remains completely undocumented: no format, default meaning, or timezone behavior is given.

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 identifies the resource as one day's heart rate and names the returned metrics (resting pulse, min/max). It is distinguishable from siblings like hrv_day, though it does not explicitly contrast itself with them.

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?

It gives one useful parameter rule: timeseries is included only when include_timeseries=true. However, it does not say when to use this tool instead of alternatives such as hrv_day or daily_summaries, nor does it clarify expected use cases.

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