slack-personal-mcp

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slack_edit_message

Idempotent

Update the text of your own Slack messages by workspace, channel, and timestamp; edits to other users' messages are refused, including with admin tokens.

Instructions

Replace the text of one of YOUR messages (chat.update, chat:write). Messages by others are refused even with an admin token. Same style gate and format as slack_send_message.

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": {
      "workspace": "<workspace>",
      "channel_id": "<channel_id>",
      "ts": "<ts>",
      "text": "<text>"
    },
    "name": "slack_edit_message"
  }
}

Input Schema

Name	Required	Default
`ts`	Yes
`text`	Yes
`format`	No	markdown
`workspace`	Yes
`channel_id`	Yes
`allow_promise`	No

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.3Oct 23, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already declare mutation, idempotency, and non-destructiveness. The description adds useful context beyond annotations: ownership enforcement even for admins, required Slack scopes, and that formatting follows slack_send_message. It does not discuss rate limits or failure modes beyond ownership refusal.

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 three short sentences, front-loaded with the core action and immediately followed by the most important constraint. Every sentence adds useful information.

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 mutation behavior and annotations, the description covers safety and ownership well, and an output schema exists. However, with six parameters and 0% schema description coverage, it leaves important parameter semantics undocumented.

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% for six parameters, so the description must carry the burden. It only clarifies that text is the replacement content and implies format follows slack_send_message, but it does not explain ts, channel_id, workspace, or allow_promise.

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 uses a specific verb and resource: replace the text of one of YOUR messages. It distinguishes this from sending and deleting messages by stating the ownership constraint and naming the underlying Slack API methods.

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?

It clearly states the primary condition for use: only your own messages can be edited, and messages by others are refused even with an admin token. It does not explicitly compare against delete_message or send_message alternatives, but the ownership constraint gives strong practical guidance.

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