Slack MCP Server

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

With no annotations provided, the description carries full burden but only states the basic action. It doesn't disclose behavioral traits like required permissions, rate limits, whether the change is reversible, or how it handles errors. The mention of a return dictionary adds minimal value beyond the output schema.

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 well-structured with a clear purpose statement followed by Args and Returns sections, making it easy to parse. It's concise with no wasted sentences, though the formatting could be slightly more front-loaded for immediate clarity.

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?

Given the tool's moderate complexity (a mutation with 2 parameters), no annotations, and an output schema present, the description is minimally adequate. It covers the basic action and parameters but lacks context on permissions, error handling, or integration with sibling tools, which would enhance completeness for safe agent use.

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?

The description adds some meaning by explaining 'channel_id' as an ID with an example format and 'topic' as new text, which compensates for the 0% schema description coverage. However, it doesn't detail constraints (e.g., topic length limits or channel ID validation), leaving gaps in parameter understanding.

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 ('Set') and resource ('topic for a Slack channel'), making the purpose immediately understandable. However, it doesn't explicitly differentiate from siblings like 'update_message' or 'create_channel' that might also modify channel properties, though the specificity of 'topic' provides some implicit distinction.

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?

No guidance is provided on when to use this tool versus alternatives. For example, it doesn't mention prerequisites (e.g., needing channel access or admin permissions) or compare to other channel-modification tools in the sibling list, leaving the agent to infer usage context.

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