Quantified Self MCP Server

Overview Schema Source Related Servers Discussions Admin

Get metric history

get_metric_history

Read-onlyIdempotent

Retrieve day-by-day values for one health metric over a date range, avoiding extra metrics from full health data. Use to review trends like weight or heart rate changes.

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.

Schema Changelog

Changes observed during successful MCP inspections.

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

A4.4/5.0

Behavior4/5

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

Annotations already mark the operation readOnlyHint and idempotentHint, and the description adds a useful privacy/data-sharing caveat plus the fact that the result is single-metric and day-by-day. This goes beyond annotations without contradicting them.

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?

The description is organized into clear sections: purpose, when/not-to-use, and privacy, with the most important information front-loaded. It is slightly longer than necessary for a simple read tool, but every section earns its place.

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?

For a read-only, idempotent tool with one required parameter and an output schema, the description covers behavior, selection criteria, alternatives, and privacy implications. There are no major gaps an agent would need to resolve.

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?

All parameters are documented in the schema (100% coverage), including formats and defaults, so the description does not need to repeat them. It adds context about selecting a single metric but does not materially improve on the schema's parameter documentation.

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?

The description opens with 'Read one metric's day-by-day values', naming a specific verb, resource, and temporal granularity, and immediately distinguishes itself from read_health_data by noting it omits the other six metrics. This makes the tool's scope unmistakable for an agent.

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?

It gives explicit 'Use this tool when' and 'Do not use this tool when' guidance, includes concrete user-phrase examples, and names read_health_data as the alternative for broad multi-metric requests. No inference is required.

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

Deploy Server