woow_emqx_mcp_server

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Unsubscribe Client From Topic

emqx_client_unsubscribe

DestructiveIdempotent

Remove a client's subscription to a specific topic, immediately stopping that device from receiving further messages for it.

Instructions

[DESTRUCTIVE] Remove a subscription from a client on its behalf.

The device stops receiving that topic immediately and has no way to tell why.

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": {
      "clientid": "<clientid>",
      "topic": "<topic>"
    },
    "name": "emqx_client_unsubscribe"
  }
}

Input Schema

Name	Required	Description	Default
`topic`	Yes	Exact topic filter to remove.
`clientid`	Yes	Client id to act for.

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 3, 2026

TDQS

A4/5.0

Behavior4/5

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

The annotations already declare destructiveHint=true and idempotentHint=true. The description adds valuable context: the device stops receiving the topic immediately and has no way to tell why. This goes beyond the annotations by explaining the immediate effect and the lack of client notification, which is important behavioral information for an agent deciding whether to call this tool.

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?

The description is two sentences long and front-loaded with a [DESTRUCTIVE] tag. It communicates the purpose and a key behavioral consequence without any filler. Every sentence earns its place, making it highly efficient for an agent to parse.

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?

Given the tool's low complexity (2 parameters, no nested objects), the annotations (destructive, idempotent, openWorld), the complete schema descriptions, and the presence of an output schema, the description covers the essential behavioral context. It could add a note about idempotency or edge cases like unsubscribing from a non-existent subscription, but these are not critical for basic usage. Overall, it is sufficiently complete.

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?

The input schema already provides clear descriptions for both parameters: topic ('Exact topic filter to remove.') and clientid ('Client id to act for.'). Schema coverage is 100%, so the description does not need to add parameter details. The description's phrase 'on its behalf' slightly reinforces the clientid semantics but does not materially improve on the schema.

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 clearly states the action: 'Remove a subscription from a client on its behalf.' This distinguishes it from sibling tools like emqx_client_subscribe (which adds a subscription) and emqx_kick_client (which disconnects a client). The verb 'Remove' and the resource 'subscription' are specific and unambiguous.

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?

The description implies when to use the tool—when you need to remove a client's subscription to a topic. However, it does not explicitly mention alternatives or exclusions. For example, it does not say 'To add a subscription, use emqx_client_subscribe' or clarify when to use this instead of emqx_kick_client. The usage context is implied but not fully articulated.

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