slack-mcp

create_channel

Destructive

Create a Slack channel by providing a channel name and setting it as public or private, receiving the channel ID on success.

Instructions

Create a new Slack channel.

Args: name: Channel name (will be sanitized: lowercase, hyphens, no spaces) is_private: Create as private channel (default: False for public)

Returns: Channel ID on success, None on failure

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": {
      "name": "<name>"
    },
    "name": "create_channel"
  }
}

Input Schema

Name	Required	Description	Default
`name`	Yes
`is_private`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 30, 2026

TDQS

A4.6/5.0

Behavior4/5

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

Annotations already indicate a non-read-only, state-changing tool. The description adds useful behavioral detail beyond annotations, including name sanitization, the default for is_private, and the return contract of Channel ID or None. This is valuable context for predicting tool behavior.

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 compact and front-loaded with the core purpose, followed by a structured Args/Returns breakdown. Every sentence provides necessary information with no filler.

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?

For a low-complexity tool with two parameters and an output schema present, the description covers the essential operational details: channel creation, parameter semantics, defaults, and failure return. Nothing critical is missing for correct invocation.

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?

The input schema has 0% description coverage, but the description fully compensates by explaining both parameters: name's sanitization rules and is_private's default and meaning. This is exactly the semantic information an agent needs beyond raw types.

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 states 'Create a new Slack channel' with a specific verb and resource, clearly distinguishing it from siblings like join_channel and rename_channel. The purpose is immediately obvious 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 Guidelines4/5

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

The description clearly indicates this tool is for creating new channels, which is a distinct use case from joining, renaming, or messaging. It does not explicitly name alternatives or exclusion conditions, but the usage context is clear enough for an agent to route correctly.

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