Get Slack user details

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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description adds nothing beyond that — no mention of permission requirements for reading profiles, rate limits, or what happens when the identifier fails to resolve.

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?

One front-loaded sentence with the action, scope, and identifier forms in the first clause; nothing is padded. It is close to minimal but could carry one more clause of routing or behavior without bloat.

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 simple one-parameter read with no output schema, the description still does not indicate what 'profile details' includes (display name, email, title, timezone) or the shape of the result, leaving the agent guessing at return contents.

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% and the single parameter already documents 'User ID (U…), email address, or @handle'. The description restates the same accepted formats without adding new meaning such as precedence between them, so it sits at the baseline.

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?

Names a specific verb and resource ('Get profile details for one Slack user') and scopes it to a single user, which implicitly separates it from the list-oriented users_search. It never names that sibling, so the differentiation is inferred rather than stated.

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?

Usage is implied by 'one Slack user' versus the sibling users_search and whoami, but the description never says explicitly when to pick this tool over those alternatives, nor any prerequisite such as needing a user ID from a search first.

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