garmin_body_batteryGet daily Body Battery charge and drain values for any date range, defaulting to the last 7 days, to track energy recovery and expenditure.
Body Battery charge and drain per day over a date range (default: last 7 days).
| Name | Required | Description | Default |
|---|---|---|---|
| end | No | ||
| start | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.4.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=true and openWorldHint=true, so the agent knows it's a safe read. The description adds that it returns charge and drain per day and the default date range, which is helpful but doesn't cover behaviors like pagination, rate limits, or error conditions. Given the annotations, a score of 3 is appropriate.
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 sentence with no filler. It front-loads the core purpose and appends the date-range default, which is efficient and easy to parse.
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 has only two parameters and an output schema, so the missing piece is parameter semantics. The description says 'over a date range' but doesn't explain how to specify start/end, what null means, or the date format. Since schema coverage is 0%, this is a significant gap that leaves the agent guessing on custom ranges.
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. It mentions a date range and a default of last 7 days, implying start and end control the range, but it doesn't specify date formats, what null means, or how the default is applied. This is insufficient compensation for the lack of schema descriptions.
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 (Body Battery) and the type of data (charge and drain per day). It distinguishes from sibling tools by naming the specific metric, though it lacks an explicit verb like 'retrieve' or 'get'. The default date range adds clarity.
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 provides no guidance on when to use this tool versus the many sibling health-data tools (e.g., garmin_heart_rate, garmin_stress). It only states what it does and the default range, without exclusions or alternatives.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.