Get HRV daily summaries (date range)

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

Annotations already declare readOnly, idempotent, non-destructive, open-world, so safety is covered; the description adds valuable output-shape context by specifying one record per day and which fields are included and excluded. It doesn't mention date-range limits, pagination, or response size, which would matter for a ranged query.

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?

A single compact sentence pair with the resource and granularity front-loaded, followed by the field list and the use case. Every clause carries information; nothing is redundant with the title.

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?

With no output schema, the description usefully compensates by listing the returned metrics and clarifying what is omitted. Parameters are fully documented in the schema, so the only remaining gap is operational detail such as range limits or maximum span.

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 100% and both fromDate/toDate already document format, inclusivity, and local-calendar semantics. The description only restates that a date range is required, adding no syntax or boundary guidance beyond the schema, so the baseline of 3 applies.

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 names a specific verb (Get), resource (HRV daily summary), and granularity (one per day over a date range), then enumerates the returned fields (weeklyAvg, lastNightAvg, baseline, status, feedback). The clause 'without the 5-minute readings' implicitly separates it from the detailed garmin_get_hrv tool, so an agent can pick between them without opening a schema.

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?

'Use for HRV trends and recovery analysis' gives clear positive guidance on the scenario this tool serves, and the exclusion of 5-minute readings scopes it. It stops short of explicitly naming garmin_get_hrv as the alternative for intraday readings, so the when-not is inferred rather than stated.

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