google-health-mcp

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health_get_cardio_fitness

Fetches estimated cardio fitness (VO2 max) readings from Google Health for a date range, using cached data or refreshing live from the API.

Instructions

Get Cardio Fitness Score (VO2 Max estimate).

Estimated from resting HR, HR during walks and runs, and demographics. Updates roughly weekly. Returns from cache by default, auto-syncing if stale.

Args: start_date: Start date as "YYYY-MM-DD", "YYYY-MM", or "30d". Default: last 30 days. end_date: End date as "YYYY-MM-DD". Default: today. live: If true, re-fetch this window from the API before reading the cache.

A reading usually carries a range or a single value; one re-synced across the switchover between providers can hold both. They are different measurements - do not average them together or fill one from the other. vo2_max_low and vo2_max_high are a reported band (e.g. 39-43); vo2_max is a single figure. All in mL/kg/min, higher being better cardiorespiratory fitness. Beside a single figure Google may report cardio_fitness_level (POOR to EXCELLENT), estimated (1 or 0), vo2_max_covariance and data_source (the device and platform it says recorded it).

Input Schema

TableJSON Schema

Name	Required	Description	Default
`live`	No
`end_date`	No
`start_date`	No

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 20, 2026

TDQS

A4.4/5.0

Behavior4/5

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

With no annotations, the description carries the full burden and does well: it discloses cache-by-default, auto-sync-on-stale semantics, ~weekly update cadence, and the important trap that two readings may be different measurements that must not be averaged or filled. It doesn't cover auth requirements or rate limits, so it falls short of a 5.

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 the purpose, then derivation, cadence, and caching before the Args block. It is longer than average, but nearly every sentence addresses a real ambiguity; the semantic discussion of vo2_max fields is dense but earns its place.

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

Completeness4/5

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

An output schema exists, so return-field definitions are not strictly required, yet explaining vo2_max vs vo2_max_low/high and the do-not-average rule prevents real misinterpretation. Combined with cache/live semantics and param formats, the definition is complete enough to call correctly.

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

Parameters5/5

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

Schema description coverage is 0%, so the description must compensate and it does: it documents all three params and adds accepted date formats ('YYYY-MM-DD', 'YYYY-MM', '30d') and the meaning of live that the bare schema does not convey.

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 (Cardio Fitness Score / VO2 Max estimate) and immediately explains how the metric is derived (resting HR, HR during walks/runs, demographics). This is distinguishable from every sibling, each of which targets a different health metric.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

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

Explains the cache-first default and when to override it with live=true, plus the default window behavior. It does not explicitly name a sibling alternative or an exclusion, but for a per-metric getter the usage context is clear enough to act on.

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