garmin-owl

Overview Schema Source Related Servers Discussions Admin

get_hrv

Read-only

Retrieve one night's Garmin HRV status, last-night and weekly averages, and personal baseline range for a given date. Use it to check heart-rate variability detail on a single morning.

Instructions

Get one night's Garmin HRV: status, last-night and weekly averages, and the personal baseline range, with optional readings.

Use for HRV detail on one date; use get_recovery to combine it with sleep and readiness, or get_recovery_trend for change over several days. The date is the day you woke up.

Field notes: values are milliseconds measured during sleep. weekly_average_ms is Garmin's rolling 7-day mean; status compares it with the baseline_low_ms-baseline_high_ms range. timeseries readings have ISO 8601 times with an explicit UTC offset, already local. When Garmin has no HRV for the night, availability says so.

Requires saved local Garmin authentication (garmin-owl-auth). Reads Garmin and may update the local cache; never changes your Garmin account. Garmin failures are not retried automatically.

Input Schema

Name	Required	Description	Default
`date`	No	Calendar date in YYYY-MM-DD format, e.g. 2026-10-09; any past date Garmin still stores. Omit or pass null for today in the server's local timezone.
`include_timeseries`	No	When true, also return timeseries: up to 48 {timestamp, value} readings sampled evenly across the day (first and last always kept), with ISO 8601 timestamps that include the UTC offset. Always reads Garmin fresh instead of the cached daily summary. Defaults to false.

Output Schema

Name	Required	Description	Default
`date`	Yes
`status`	No
`timeseries`	No
`availability`	No
`baseline_low_ms`	No
`baseline_high_ms`	No
`weekly_average_ms`	No
`nightly_average_ms`	No
`last_night_average_ms`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed8 schema fields changedv0.3.1Oct 24, 2026

changedInput schema / properties / date / anyOf

Previous value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]New value: +[
+  {
+    "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+    "type": "string"
+  },
+  {
+    "type": "null"
+  }
+]

addedInput schema / properties / date / description

Added value: +"Calendar date in YYYY-MM-DD format, e.g. 2026-10-09; any past date Garmin still stores. Omit or pass null for today in the server's local timezone."

addedInput schema / properties / include_timeseries / description

Added value: +"When true, also return timeseries: up to 48 {timestamp, value} readings sampled evenly across the day (first and last always kept), with ISO 8601 timestamps that include the UTC offset. Always reads Garmin fresh instead of the cached daily summary. Defaults to false."

addedOutput schema / $defs

Added value: +{
+  "AvailabilityNotice": {
+    "properties": {
+      "field": {
+        "title": "Field",
+        "type": "string"
+      },
+      "message": {
+        "title": "Message",
+        "type": "string"
+      },
+      "status": {
+        "title": "Status",
+        "type": "string"
+      }
+    },
+    "required": [
+      "field",
+      "status",
+      "message"
+    ],
+    "title": "AvailabilityNotice",
+    "type": "object"
+  },
+  "TimePoint": {
+    "properties": {
+      "timestamp": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "integer"
+          }
+        ],
+        "description": "Reading time: ISO 8601 with an explicit UTC offset, e.g. 2026-10-09T23:18:16+02:00. The wall time is already local; never add the offset again. The offset is the one Garmin recorded for the device at that moment, or this computer's time zone when Garmin gives only UTC. A bare date or number is a Garmin value that could not be parsed as a time.",
+        "title": "Timestamp"
+      },
+      "value": {
+        "anyOf": [
+          {
+            "type": "number"
+          },
+          {
+            "type": "integer"
+          }
+        ],
+        "title": "Value"
+      }
+    },
+    "required": [
+      "timestamp",
+      "value"
+    ],
+    "title": "TimePoint",
+    "type": "object"
+  }
+}

removedOutput schema / additionalProperties
```
Removed value: -true
```

addedOutput schema / properties

Added value: +{
+  "availability": {
+    "items": {
+      "$ref": "#/$defs/AvailabilityNotice"
+    },
+    "title": "Availability",
+    "type": "array"
+  },
+  "baseline_high_ms": {
+    "anyOf": [
+      {
+        "type": "number"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "title": "Baseline High Ms"
+  },
+  "baseline_low_ms": {
+    "anyOf": [
+      {
+        "type": "number"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "title": "Baseline Low Ms"
+  },
+  "date": {
+    "title": "Date",
+    "type": "string"
+  },
+  "last_night_average_ms": {
+    "anyOf": [
+      {
+        "type": "number"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "title": "Last Night Average Ms"
+  },
+  "nightly_average_ms": {
+    "anyOf": [
+      {
+        "type": "number"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "title": "Nightly Average Ms"
+  },
+  "status": {
+    "anyOf": [
+      {
+        "type": "string"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "title": "Status"
+  },
+  "timeseries": {
+    "anyOf": [
+      {
+        "items": {
+          "$ref": "#/$defs/TimePoint"
+        },
+        "type": "array"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "title": "Timeseries"
+  },
+  "weekly_average_ms": {
+    "anyOf": [
+      {
+        "type": "number"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "title": "Weekly Average Ms"
+  }
+}

addedOutput schema / required
```
Added value: +[
+  "date"
+]
```

changedOutput schema / title

Previous value: -"get_hrvDictOutput"New value: +"HrvSummary"

First observedv0.1.0Aug 31, 2026

TDQS

A4.6/5.0

Behavior4/5

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

Annotations already cover the read-only/non-destructive profile, yet the description still adds real context: saved local Garmin auth requirement, that it may update the local cache, that it never mutates the Garmin account, and that failures are not retried. It also explains unit semantics (milliseconds during sleep), what weekly_average_ms means, and how status relates to the baseline range. Minor gap: no note on latency/cost of the fresh-fetch path beyond the schema's own text.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose, then routing, then field notes, then auth/caveats — a good priority order with no filler sentences. Slightly dense in the field-notes block and the opener's 'with optional readings' is vaguer than the rest, keeping it short of a 5.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers everything an agent needs: purpose, alternatives, auth prerequisite, cache behavior, failure handling, unit semantics, and the no-data case ('availability says so'). With an output schema present, it correctly avoids restating the return structure while still flagging the meaning of key fields.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3. The description nonetheless adds meaning by defining date as the wake-up day and by characterizing readings as sleep-time measurements with explicit UTC offsets already localized. That is genuine semantic value, though most parameter mechanics still live in the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Get one night's Garmin HRV') and enumerates what comes back: status, last-night and weekly averages, baseline range, optional readings. It also names the sibling tools it is not (get_recovery, get_recovery_trend), so an agent can discriminate 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.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit routing: 'Use for HRV detail on one date; use get_recovery to combine it with sleep and readiness, or get_recovery_trend for change over several days.' It also disambiguates the date parameter's meaning ('the day you woke up'), removing the main usage ambiguity.

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