lookup_user

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

Annotations already declare readOnlyHint=true, and the description's 'Search' wording aligns with this. However, the description does not add any extra behavioral context such as pagination semantics, result shape, or rate limits, so it contributes minimal value beyond the annotation.

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 a single, focused sentence that immediately communicates the tool's purpose with no filler. It is well-structured and front-loaded, making it easy to parse.

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 simplicity of the tool and the comprehensive schema plus read-only annotation, the description is mostly sufficient. It could benefit from naming the output format or potential limitations, but the core usage is clearly captured, making it complete enough for a basic search tool.

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 covers all three parameters (query, page, per_page) with full descriptions, achieving 100% coverage. The tool description does not enrich the parameter semantics beyond what the schema already provides, so a baseline score of 3 is appropriate.

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 action ('Search'), resource ('RT users'), and scope ('by name or email address'). It distinguishes itself from sibling tools like search_tickets (ticket search) and get_current_user (current user) by specifying the user-focused lookup nature.

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 clear context for when to use this tool—whenever a user needs to be found by name or email. It does not explicitly mention alternatives or when not to use it, but the purpose is sufficiently self-evident from the wording.

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