get_user_info

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

Indicates read operation but lacks details on authentication, rate limits, error handling, or what happens if both parameters are provided. No annotations to supplement.

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?

Three concise sentences with clear purpose and parameter descriptions, no wasted words.

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?

Covers purpose, parameters, and usage constraint; output schema exists. Could mention error handling or authentication, but adequate for a simple lookup.

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?

Adds meaning beyond schema by specifying format ('without @' for screen_name, 'numeric ID' for user_id) and the exclusive OR constraint.

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 retrieves user profile metadata by screen name or user ID, distinguishing it from sibling tools like search_user or get_user_followers.

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?

Explicitly requires exactly one identifier, but no guidance on when not to use or alternatives beyond the parameter constraint.

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