Cronometer MCP

get_nutrition_summary

Read-onlyIdempotent

Retrieve daily macro totals and averages across a date range, optionally adding specific nutrients, to review Cronometer nutrition logs and trends.

Instructions

Daily macro totals over a range of days, with averages.

Each day carries energy, protein, carbs, net carbs, fat, fiber and alcohol. Days with nothing logged are listed but left out of the averages. Pass nutrient names (e.g. ["vitamin_d", "iron"]) to add those as well. At most 62 days per call.

Args: start_date: First day, YYYY-MM-DD. end_date: Last day, YYYY-MM-DD (defaults to today). nutrients: Extra nutrient names to include, as in list_nutrients.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "start_date": "<start_date>"
    },
    "name": "get_nutrition_summary"
  }
}

Input Schema

Name	Required	Description	Default
`end_date`	No
`nutrients`	No
`start_date`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.1.0Nov 14, 2026

TDQS

A3.9/5.0

Behavior4/5

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

Beyond the annotations (readOnly/idempotent/non-destructive/openWorld already declare the safety profile), the description adds genuinely useful behavior: days with nothing logged are listed but excluded from averages, and there is a hard 62-day-per-call cap. It does not say whether exceeding 62 days errors or truncates, which is a real gap for a capped-range tool.

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 aggregation behavior, then scope caveats, then a compact Args block. The Args section would normally duplicate the schema, but since schema coverage is 0% it earns its place; the only mild redundancy is restating defaults already present in the schema.

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?

An output schema exists, so return values need not be explained, and the description still covers aggregation rules, empty-day handling, optional extra nutrients, date defaults and the range cap. For a 3-parameter read-only query this is complete enough to invoke correctly.

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 description coverage is 0%, so the description carries the full burden and mostly does: dates are specified as YYYY-MM-DD, end_date defaults to today, and nutrients is explained as a list of names 'as in list_nutrients'. The nutrients arg could say more about output shape or whether unknown names are rejected, but the core semantics are supplied.

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

Purpose4/5

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

The opening line states a concrete resource and aggregation shape: 'Daily macro totals over a range of days, with averages', plus the nutrient list it returns (energy, protein, carbs, net carbs, fat, fiber, alcohol). That is enough to distinguish it from a single-day tool, but it never names a sibling such as get_daily_nutrition, so differentiation is left to inference.

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

Usage Guidelines3/5

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

Usage is implied rather than stated: a multi-day range with averages, capped at 62 days per call, suggests it is the tool for trend/range queries. There is no explicit 'use this instead of get_daily_nutrition when...' guidance and no prerequisites noted, so the agent must infer the boundary from the word 'range'.

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

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