slack_user_info

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

No annotations provided, so description carries full burden. Describes read-only behavior, return fields (display name, real name, timezone), and explicitly notes email omission. Does not cover rate limits or error states, but adequate for simple lookup.

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 efficient sentences with no fluff. Front-loaded with purpose and key constraints.

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?

Complete for a simple one-parameter lookup tool. Specifies output fields and intentional omission. Lacks details on missing user behavior, but acceptable without output schema.

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 coverage is 100% (one parameter well-described). Description adds no additional parameter details beyond mentioning lookup by id, but baseline 3 is appropriate given complete schema.

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?

Clear verb 'look up' and resource 'Slack user by id'. Specifies returned fields and intentionally omitted email. Distinguishes from sibling tools like slack_list_users that list all users.

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?

Implies usage for individual user lookup but no explicit guidance on when to use vs. slack_list_users (retrieve all users) or when not to use. No context on prerequisites or error handling.

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