Slack MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool lists channels but doesn't mention pagination behavior (implied by 'cursor' parameter), rate limits, authentication requirements, or what the return format looks like (no output schema). For a list operation with 4 parameters, this leaves significant behavioral gaps.

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?

The description is a single, efficient sentence that immediately conveys the core functionality without unnecessary words. It's appropriately sized for a list operation and front-loads the essential information ('List all Slack channels').

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 tool with 4 parameters, no annotations, and no output schema, the description is insufficiently complete. It doesn't address behavioral aspects like pagination, return format, or error conditions, nor does it provide usage guidance relative to sibling tools. The 100% schema coverage helps with parameters but doesn't compensate for other contextual gaps.

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 fully documents all 4 parameters. The description adds no additional parameter semantics beyond what's in the schema (e.g., it doesn't explain the 'types' parameter values or 'cursor' usage). Baseline 3 is appropriate when the schema does all the parameter documentation work.

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?

The description clearly states the verb ('List') and resource ('all Slack channels') with scope ('public and private accessible to the user'), making the purpose immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'slack_get_channel_info' or 'slack_list_workspaces', which would require more specific comparison context.

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 provides no guidance on when to use this tool versus alternatives like 'slack_get_channel_info' (for single channel details) or 'slack_list_workspaces' (for listing workspaces instead of channels). It mentions scope ('accessible to the user') but offers no explicit when/when-not instructions or sibling tool comparisons.

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