MCP OpsBridge

slack_send_thread_reply

Send a reply in a Slack thread using the channel ID and thread timestamp. Approval is required before the message is sent.

Instructions

Send a reply in a Slack thread (requires approval)

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": "<channel>",
      "thread_ts": "<thread_ts>",
      "text": "<text>"
    },
    "name": "slack_send_thread_reply"
  }
}

Input Schema

Name	Required	Description
`text`	Yes	Reply text
`channel`	Yes	Channel ID
`thread_ts`	Yes	Timestamp of the parent message

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.0.0Aug 10, 2026

TDQS

A3.6/5.0

Behavior3/5

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

With no annotations, the description carries the entire burden. It discloses that approval is required, which is a meaningful behavioral trait, but it does not explain the approval process, whether the reply is sent immediately upon approval, or what happens if approval is denied. This is a partial disclosure that leaves important gaps.

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 a single concise sentence that immediately communicates the core action and a key constraint. It contains no redundant words or irrelevant details, making efficient use of the space.

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?

The description is minimal and leaves critical context unexplained, particularly regarding the approval workflow and the relationship with approve_action. With no annotations and no output schema, the agent lacks information about return values or failure behavior, which is necessary for a complete understanding of the tool's operation.

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 descriptions for all three parameters, achieving 100% coverage. The tool description adds no additional semantic information beyond what the schema contains, so the baseline score of 3 applies.

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 ('Send a reply') and the specific resource ('in a Slack thread'), which distinguishes it from the sibling tool slack_send_message for direct messages. The addition of 'requires approval' provides extra context without obscuring the primary purpose.

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?

No explicit when-to-use or alternatives are provided. The thread-specific phrasing implies it is for replying to existing threads, and the mention of approval hints at a workflow, but there is no guidance on when to select this tool over slack_send_message or how it relates to approve_action.

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