slack-mcp

post_command

Destructive

Post a command to a Slack channel using channel ID, command, and text. Triggers slash commands or bot actions directly in the workspace.

Instructions

Post a command to a channel.

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": {
      "channel_id": "<channel_id>",
      "command": "<command>",
      "text": "<text>"
    },
    "name": "post_command"
  }
}

Input Schema

Name	Required	Description	Default
`text`	Yes
`command`	Yes
`skip_log`	No
`channel_id`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Aug 30, 2026

TDQS

C2.9/5.0

Behavior3/5

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

The annotations already indicate readOnlyHint=false, destructiveHint=true, and openWorldHint=true, so the description does not contradict the safety profile. However, it adds no extra behavioral context, such as whether the command is executed, what side effects it may have, or whether it requires special permissions.

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?

The description is a single short sentence with no wasted words and the key action is front-loaded. It is concise, though the brevity comes at the cost of useful detail that other dimensions require.

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

Completeness2/5

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

For a destructive, open-world mutation tool with four parameters and a sibling post_message, this description is too sparse. It does not explain what a 'command' is, how it differs from a normal message, or what side effects the caller should expect, leaving important context missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, and the description only weakly illuminates the parameters: 'command' and 'channel' align with the command and channel_id fields, but text and skip_log remain completely unexplained. The description does not compensate for the missing schema parameter 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 states a clear verb and resource: 'Post a command to a channel.' It is understandable and partially distinguishes this tool from the sibling post_message by using 'command' rather than 'message', but it does not explicitly contrast the two.

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 given about when to use this tool versus alternatives such as post_message, send_dm, or send_group_dm. The intended usage is only implied by the tool name and the terse description, with no exclusions or conditions provided.

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