Retrieve original sleep, HRV, or heart-rate data for one calendar date so you can inspect daily health metrics without treating missing measurements as zero.
Read original sleep, HRV or heart-rate data for one explicit calendar date. A missing measurement is not zero. HRV/heart rate alone cannot diagnose recovery or health.
| Name | Required | Description | Default |
|---|---|---|---|
| date | Yes | ||
| metric | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so safety is covered; the description adds genuinely new semantics on top of that. 'A missing measurement is not zero' discloses data-sparsity behavior that an agent would otherwise misread, and the diagnostic caveat sets interpretation limits. It still says nothing about return shape or units.
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?
Three short sentences with the core purpose front-loaded, followed by two caveats. Every sentence is short and the caution lines do real work, though the diagnostic disclaimer sits close to boilerplate.
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 simple two-parameter read tool the description is adequate, but there is no output schema and the description never indicates what a day-detail payload contains (sleep stages vs. HRV samples, units, granularity). An agent knows how to call it but not what to expect back.
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 carry the load; it clarifies that the date must be an explicit single calendar date and enumerates the three metrics matching the enum. Beyond that, it adds no format, timezone, or selection detail for the two required parameters, so the gain is modest for self-evident names.
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 and resource ('Read original sleep, HRV or heart-rate data') and constrains scope to 'one explicit calendar date', which implicitly separates it from the range-based sibling garmin_get_health_range. It does not name that sibling outright, so the differentiation is inferred rather than stated.
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?
Usage is only implied: the single-date phrasing hints that this is the tool for one day's raw values rather than a range, but no explicit when-to-use or when-not-to-use statement is given, and no alternative tool is named. The remaining sentences are interpretive caveats rather than routing guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.