Slack MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions what the tool does and the return value, but lacks details on permissions, error handling (e.g., if user not found), rate limits, or other behavioral traits. The description is minimal and does not adequately cover behavioral aspects beyond basic functionality.

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 appropriately sized and front-loaded: the first sentence states the purpose clearly, followed by structured 'Args' and 'Returns' sections. Every sentence adds value without waste, making it efficient and well-organized.

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 low complexity (one parameter) and the presence of an output schema (which handles return values), the description is complete enough for basic use. It covers purpose, parameters, and returns, but could be improved with more behavioral context. The output schema reduces the need for detailed return explanations, making this reasonably complete.

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 meaning by specifying that the 'email' parameter is 'The email address to look up,' which clarifies its purpose beyond the schema's title 'Email.' However, schema description coverage is 0%, and the description does not compensate with additional details like format requirements or examples. With one parameter and some added semantics, it meets the baseline but lacks depth.

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 tool's purpose: 'Find a user by their email address.' It specifies the verb ('Find') and resource ('user'), but does not distinguish it from sibling tools like 'get_user_info' or 'get_user_profile', which might serve similar purposes. The purpose is clear but lacks sibling differentiation.

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. It does not mention sibling tools like 'get_user_info' or 'get_user_profile', nor does it specify contexts or exclusions for usage. There is implied usage based on the purpose, but no explicit guidelines are provided.

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