Nightscout MCP Server

get_device_status

Check current diabetes device status: pump reservoir/battery, sensor, loop, IOB, COB, and predictions to assess system health.

Instructions

Get device status: pump reservoir/battery, sensor info, loop status, active IOB (insulin on board), COB (carbs on board), and predictions. Shows the current state of the diabetes management system.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "get_device_status"
  }
}

Input Schema

Name	Required	Description	Default
`count`	No	Number of recent statuses (default 1)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.4.0Sep 6, 2026

TDQS

A4.2/5.0

Behavior4/5

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

With no annotations, the description carries the safety/behavior burden. It signals a non-mutating read via 'Get' and 'Shows' and describes the returned status categories. It does not mention staleness, data source caveats, or response structure, but for a getter of this scope the disclosure is adequate.

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

Conciseness5/5

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

Two sentences with no filler; the main result is front-loaded and the items are a compact list. Every phrase adds information.

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?

The tool is simple (one optional parameter) and the schema documents that parameter. The description covers the purpose and the categories returned. It leaves output formatting details unspecified, but no output schema exists and the itemized list is enough for an agent to decide whether to call it.

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 coverage is 100%: the only parameter, count, has a description, min/max, and default in the schema. The tool description adds nothing about count beyond calling them 'recent statuses', so a baseline 3 is appropriate.

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 uses a specific verb ('Get') and resource ('device status') and enumerates the concrete contents (reservoir/battery, sensor info, loop status, IOB, COB, predictions). This distinguishes it from siblings like get_current_glucose or get_glucose_history even without naming them.

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?

It clearly frames the tool as a current-state snapshot ('Shows the current state of the diabetes management system'), which tells an agent when to choose it over history/statistics tools. It does not explicitly list exclusions or alternative tool names.

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