Skip to main content
Glama
bcharleson

Slack MCP Server

list_channels

Retrieve accessible Slack channels in your workspace with options to filter by channel type, exclude archived channels, and limit results.

Instructions

    List all accessible Slack channels in the workspace.

    Args:
        types: Comma-separated channel types to include.
               Options: public_channel, private_channel, mpim, im
               Default: "public_channel,private_channel"
        exclude_archived: Whether to exclude archived channels. Default: True
        limit: Maximum number of channels to return (1-1000). Default: 100

    Returns:
        Dictionary containing list of channels with their details
    

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
typesNopublic_channel,private_channel
exclude_archivedNo
limitNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault

No arguments

Behavior2/5

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

With no annotations provided, the description carries full burden but only minimally addresses behavior. It mentions returning a dictionary with channel details but doesn't disclose pagination, rate limits, authentication needs, or error handling. This is inadequate for a tool with potential complexity.

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 well-structured with a clear purpose statement followed by detailed parameter explanations in a formatted Args/Returns section. Every sentence adds essential information without redundancy, making it efficient and easy to parse.

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?

Given the tool's moderate complexity (3 parameters, no annotations) and the presence of an output schema (implied by 'Returns'), the description is partially complete. It covers parameters well but lacks behavioral context like permissions or error cases, leaving gaps despite the output schema.

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 description adds significant value beyond the input schema, which has 0% coverage. It explains each parameter's purpose, options for 'types', defaults, and constraints like 'limit' range (1-1000), compensating fully for the schema's lack of descriptions.

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 clearly states the verb ('List') and resource ('all accessible Slack channels in the workspace'), providing a specific purpose. It distinguishes from siblings like 'list_conversations' by specifying 'channels' rather than generic conversations, though it doesn't explicitly contrast them.

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?

No guidance is provided on when to use this tool versus alternatives like 'list_conversations' or 'search_all'. The description lacks context about prerequisites, such as required permissions or workspace access, leaving usage unclear.

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

Install Server

Other Tools

Latest Blog Posts

MCP directory API

We provide all the information about MCP servers via our MCP API.

curl -X GET 'https://glama.ai/api/mcp/v1/servers/bcharleson/slack-mcp-server'

If you have feedback or need assistance with the MCP directory API, please join our Discord server