Retrieve messages matching a query across the Slack workspace. Requires a user token (xoxp-) with search:read permission, as bot tokens are not supported.
Search for messages across the workspace. Requires a user token (xoxp-) with search:read scope — bot tokens (xoxb-) are not supported by Slack's search API.
| Name | Required | Description | Default |
|---|---|---|---|
| count | No | Number of results to return | |
| query | Yes | Search query string |
Changes observed during successful MCP inspections.
v0.1.8Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are present, so the description carries the full disclosure burden. It adds genuinely useful context by requiring a user token (xoxp-) with search:read scope and explicitly excluding bot tokens (xoxb-), a real-world constraint that prevents failed calls. However, it omits rate limits, pagination behavior, and result-return details.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two sentences with zero filler; the purpose is front-loaded and the auth constraint earns the second sentence. Efficient and appropriately sized for the tool's complexity.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a 2-param search tool with no output schema, the description covers the purpose and the critical auth constraint well. It leaves gaps around result shape and pagination, which an agent would need to handle multi-page Slack search results.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the schema already documents query and count, setting the baseline at 3. The description adds no param-level syntax, query operators, or count constraints beyond what the schema provides.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb ('Search'), resource ('messages'), and scope ('across the workspace'), which clearly distinguishes it from channel-scoped tools like list_history. However, it doesn't explicitly name or differentiate from siblings, so it stops short of a 5.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies usage as a workspace-wide message search but provides no explicit when-to-use guidance or named alternatives such as list_history for browsing a single channel. The token requirement reads as a prerequisite rather than usage direction.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.