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Get metric history

get_metric_history

Read-onlyIdempotent

Read day-by-day values for one health metric over a date range, so you can analyze a single trend without fetching the full multi-metric payload.

Instructions

Read one metric's day-by-day values, without the other six metrics read_health_data always includes. Use this when you only care about a single metric (e.g. before calling get_baseline or calculate_metric_trend yourself) and don't need the full multi-metric payload.

Use this tool when:

the user wants one specific metric's history/trend over time (e.g. "show my weight over the last 30 days", "how has resting heart rate changed this month").

Do not use this tool when:

the request is broad/general, across multiple metrics at once -> use read_health_data instead.

Privacy note: this server and its SQLite file are entirely local, but the data returned by this tool becomes part of the conversation sent to whatever model the calling client is configured with. If that model runs in the cloud rather than on your machine, treat this the same as pasting the data into a chat with that provider.

Input Schema

TableJSON Schema

Name	Required	Description
`metric`	Yes	One of steps, sleep_hours, resting_heart_rate, weight_kg, workout_minutes, mood, water_ml, heart_rate, hrv_ms. Rejected if configured as private via HEALTH_PRIVATE_FIELDS.
`end_date`	No	Last day to include, formatted YYYY-MM-DD. Defaults to today.
`start_date`	No	First day to include, formatted YYYY-MM-DD. Defaults to 30 days before end_date.

Output Schema

TableJSON Schema

Name	Required	Description
`range`	Yes
`metric`	Yes
`points`	Yes
`evidence`	Yes	Coverage/quality of the data a single-metric analytical result is based on. See evidence.build_evidence for how each field is computed.
`data_health`	No	Whether this history is complete, current and trustworthy; see DataHealth.

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.0.29Oct 3, 2026

addedOutput schema / properties / data_health

Added value: +{
+  "anyOf": [
+    {
+      "description": "Data-quality state behind one result (not a medical or statistical confidence score). status is one of\nVALID, VALID_WITH_GAPS, INSUFFICIENT_DATA, STALE, IMPORT_INCOMPLETE; reasons lists every condition that\napplies. See data_health.compose_data_health for how it is decided.",
+      "properties": {
+        "completeness": {
+          "properties": {
+            "coverage_ratio": {
+              "type": "number"
+            },
+            "expected_days": {
+              "type": "integer"
+            },
+            "missing_days": {
+              "type": "integer"
+            },
+            "observed_days": {
+              "type": "integer"
+            }
+          },
+          "required": [
+            "expected_days",
+            "observed_days",
+            "coverage_ratio",
+            "missing_days"
+          ],
+          "type": "object"
+        },
+        "coverage": {
+          "properties": {
+            "end": {
+              "anyOf": [
+                {
+                  "type": "string"
+                },
+                {
+                  "type": "null"
+                }
+              ],
+              "default": null
+            },
+            "requested_end": {
+              "type": "string"
+            },
+            "requested_start": {
+              "type": "string"
+            },
+            "start": {
+              "anyOf": [
+                {
+                  "type": "string"
+                },
+                {
+                  "type": "null"
+                }
+              ],
+              "default": null
+            }
+          },
+          "required": [
+            "requested_start",
+            "requested_end"
+          ],
+          "type": "object"
+        },
+        "freshness": {
+          "properties": {
+            "age_days": {
+              "anyOf": [
+                {
+                  "type": "integer"
+                },
+                {
+                  "type": "null"
+                }
+              ],
+              "default": null,
+              "description": "Days from the latest observation to the end of the requested window."
+            },
+            "dataset_days_behind": {
+              "anyOf": [
+                {
+                  "type": "integer"
+                },
+                {
+                  "type": "null"
+                }
+              ],
+              "default": null,
+              "description": "Days from the dataset's latest data (any metric) to today."
+            },
+            "latest_data": {
+              "anyOf": [
+                {
+                  "type": "string"
+                },
+                {
+                  "type": "null"
+                }
+              ],
+              "default": null
+            }
+          },
+          "type": "object"
+        },
+        "gaps": {
+          "items": {
+            "properties": {
+              "days": {
+                "type": "integer"
+              },
+              "end": {
+                "type": "string"
+              },
+              "start": {
+                "type": "string"
+              }
+            },
+            "required": [
+              "start",
+              "end",
+              "days"
+            ],
+            "type": "object"
+          },
+          "type": "array"
+        },
+        "last_import": {
+          "anyOf": [
+            {
+              "properties": {
+                "finished_at": {
+                  "anyOf": [
+                    {
+                      "type": "string"
+                    },
+                    {
+                      "type": "null"
+                    }
+                  ],
+                  "default": null
+                },
+                "importer": {
+                  "type": "string"
+                },
+                "source_file": {
+                  "anyOf": [
+                    {
+                      "type": "string"
+                    },
+                    {
+                      "type": "null"
+                    }
+                  ],
+                  "default": null
+                },
+                "status": {
+                  "type": "string"
+                }
+              },
+              "required": [
+                "importer",
+                "status"
+              ],
+              "type": "object"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "last_successful_import": {
+          "anyOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "observations": {
+          "description": "Number of daily values the result is computed from.",
+          "type": "integer"
+        },
+        "reasons": {
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "status": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "status",
+        "reasons",
+        "freshness",
+        "coverage",
+        "completeness",
+        "gaps",
+        "observations"
+      ],
+      "type": "object"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "description": "Whether this history is complete, current and trustworthy; see DataHealth."
+}

Changed2 schema fields changedSep 15, 2026

addedOutput schema / properties / evidence

Added value: +{
+  "description": "Coverage/quality of the data a single-metric analytical result is\nbased on. See evidence.build_evidence for how each field is computed.",
+  "properties": {
+    "confidence": {
+      "type": "string"
+    },
+    "coverage_ratio": {
+      "type": "number"
+    },
+    "expected_days": {
+      "type": "integer"
+    },
+    "freshness_days": {
+      "anyOf": [
+        {
+          "type": "integer"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "default": null
+    },
+    "gaps": {
+      "items": {
+        "properties": {
+          "days": {
+            "type": "integer"
+          },
+          "end": {
+            "type": "string"
+          },
+          "start": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "start",
+          "end",
+          "days"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "measurement_count": {
+      "type": "integer"
+    },
+    "missing_days": {
+      "type": "integer"
+    },
+    "observed_days": {
+      "type": "integer"
+    },
+    "observed_end": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "default": null
+    },
+    "observed_start": {
+      "anyOf": [
+        {
+          "type": "string"
+        },
+        {
+          "type": "null"
+        }
+      ],
+      "default": null
+    },
+    "recent_gap_days": {
+      "type": "integer"
+    },
+    "requested_end": {
+      "type": "string"
+    },
+    "requested_start": {
+      "type": "string"
+    }
+  },
+  "required": [
+    "requested_start",
+    "requested_end",
+    "expected_days",
+    "observed_days",
+    "coverage_ratio",
+    "missing_days",
+    "measurement_count",
+    "gaps",
+    "recent_gap_days",
+    "confidence"
+  ],
+  "type": "object"
+}

changedOutput schema / required

Previous value: -[
-  "metric",
-  "range",
-  "points"
-]New value: +[
+  "metric",
+  "range",
+  "points",
+  "evidence"
+]

Addedv1.0.16Sep 15, 2026
Removedv1.0.15Sep 15, 2026
Addedv1.0.11Sep 13, 2026

TDQS

A4.6/5.0

Behavior5/5

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely non-redundant context: a privacy note that returned data enters the conversation with the calling model, and that a metric configured via HEALTH_PRIVATE_FIELDS is rejected. This is meaningful behavioral disclosure beyond the structured fields.

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?

Purpose is front-loaded and the when/when-not structure is skimmable. The privacy paragraph is longer than the rest and could be tightened, but it earns its place by disclosing non-obvious data-flow behavior.

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?

Output schema exists, so return-shape explanation is unnecessary, and the description covers selection criteria, scope, and privacy caveats. Nothing an agent needs to call this read-only tool correctly is missing.

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

Parameters3/5

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

Schema description coverage is 100%, so the metric enumeration, format, and default windows for start_date/end_date are already documented in the schema. The description reinforces the single-metric framing but adds no syntax or format detail beyond the schema, so the baseline 3 is correct.

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 precise verb and resource ('Read one metric's day-by-day values') and immediately contrasts scope with the sibling read_health_data, which always returns all metrics. An agent can distinguish this tool from read_health_data and the trend/baseline siblings without opening any 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 'Use this tool when' section with concrete user-phrasing examples ('show my weight over the last 30 days') and an explicit 'Do not use this tool when' clause routing broad multi-metric requests to read_health_data. Alternatives and conditions are named, not inferred.

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