slack_profiles

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

With no annotations, the description carries the full burden and discloses key behaviors: resolves custom fields to labels, rewrites user-typed fields from IDs to display names, returns field_definitions alongside profiles, and gracefully handles unresolvable entries with error objects. It does not mention authentication or rate limits, but for a read-only lookup tool, the provided transparency is solid.

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 concise and well-structured, with a clear opening statement, a helpful comparison, and a dedicated Args section. Each sentence adds value, though the comparison could be slightly more compact without losing essential guidance.

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 has one parameter, an output schema, and no annotations, the description is complete. It covers purpose, usage, behavioral details, argument format, and error handling. No important context is missing.

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 input schema only defines 'handles' as an array of strings, but the description enriches it by specifying accepted formats ('Usernames, @usernames, or user IDs') and documenting error handling for unresolvable entries. This fully compensates for the 0% schema coverage.

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 function: 'Look up full profiles for several people at once.' It distinguishes itself from slack_user by explaining it is 'Richer than slack_user' and resolving custom fields and user-typed fields from IDs to labels, making the purpose distinct and specific.

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 explicitly provides usage guidance: 'Use slack_user for a quick single ID-to-name lookup; use this to populate records for several people.' This clearly states when to use this tool versus the alternative slack_user.

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