listmonk-mcp

Get subscriber

subscriber_get

Read-onlyIdempotent

Retrieve a single Listmonk subscriber by ID, including their list memberships, to inspect contact details and subscription status.

Instructions

One subscriber by id, including their list memberships.

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": {
      "id": "<id>"
    },
    "name": "subscriber_get"
  }
}

Input Schema

Name	Required	Description	Default
`id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 1, 2026

TDQS

B3.2/5.0

Behavior3/5

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds the useful detail that list memberships are included in the response, but says nothing about not-found behavior or the shape of the payload beyond that.

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?

A single compact sentence with the resource and lookup key front-loaded. Nothing is wasted, though the extreme brevity leaves gaps that a clause or two could have closed.

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

Completeness3/5

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

For a simple one-parameter read tool with full annotation coverage and no output schema, the description is close to sufficient. It is missing the key practical details: what happens on a missing id and how this differs from the search tool.

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?

With schema description coverage at 0%, the description is the only place 'id' gets context, and it confirms it is the subscriber id. It does not clarify format constraints (the schema uses an integer with exclusiveMinimum 0) or whether the id refers to the subscriber versus a list or user.

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 description names the resource (one subscriber) and the lookup key (id), and it signals the return payload ('including their list memberships'). It implicitly distinguishes itself from subscribers_search and subscriber_create/update, though it never uses an explicit verb like 'get' or 'fetch'.

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

Usage Guidelines2/5

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

There is no guidance on when to use this versus subscribers_search, which is the obvious alternative for finding subscribers. No prerequisites, no mention of behavior when the id doesn't exist, and no exclusions are stated.

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