slack-mcp

get_thread

Read-only

Retrieve all messages in a Slack thread using channel ID and parent message timestamp. Read the full conversation before replying to stay informed.

Instructions

Get all messages in a thread given a channel ID and the parent message timestamp.

Use this to read a full conversation thread before replying to it. The thread_ts is the timestamp of the parent message that started the thread.

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>",
      "thread_ts": "<thread_ts>"
    },
    "name": "get_thread"
  }
}

Input Schema

Name	Required	Description	Default
`limit`	No
`thread_ts`	Yes
`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

A4/5.0

Behavior3/5

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

Annotations already mark this as readOnlyHint=true, so the description does not need to restate safety. It adds context by clarifying that thread_ts is the parent message timestamp, but does not disclose ordering, pagination effects of limit, or behavior when no thread exists.

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?

Three concise sentences, each earning its place: the action, the recommended use case, and key parameter clarification. The most important identifying phrase is front-loaded.

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

Completeness4/5

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

For a simple read-only fetch with an output schema available, this is largely complete. It gives the purpose, usage context, and defines the critical parameter. The only notable omission is how limit affects returned messages, but this is optional and defaults to 100.

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?

Schema description coverage is 0%, so the description must compensate. It does explain thread_ts as 'the timestamp of the parent message' and mentions channel ID as an input. However, it ignores the optional limit parameter entirely, leaving its meaning to the schema's default.

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?

Description opens with a specific verb-resource pair: 'Get all messages in a thread' and names the two required inputs. This clearly differentiates it from sibling get_channel_history by focusing on thread context rather than channel history.

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?

Explicitly guides usage: 'Use this to read a full conversation thread before replying to it.' This gives clear context but stops short of listing alternatives or when-not-to-use conditions like get_channel_history would be preferred.

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