Get User

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

Annotations already declare readOnlyHint=true, and the description's 'Get information' aligns with that. The description adds the scope of lookup by login or UID, but this is more about parameter semantics than additional behavioral disclosure. No extra context about return format, errors, or permissions is provided, but the read-only annotation covers the safety profile.

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 concise sentence that directly communicates the tool's function and scope. Every word earns its place, with no redundancy or filler.

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 single-parameter getter with readOnly annotation and an output schema available, the description is sufficient. It clearly identifies what the tool does, and the schema handles parameter details, so no additional context is needed.

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 already provides 100% coverage, including a clear description of user_id as accepting either a login or UID with examples. The tool description adds no new parameter information, so it neither enhances nor detracts from the schema 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?

Description uses a specific verb ('Get') and resource ('information about a specific user') with clear identifier scope ('by login or UID'). It distinguishes from sibling tools like users_get_all, users_search, and user_get_current by emphasizing a single specific user lookup.

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 clearly implies usage when a specific user identifier (login or UID) is known, which guides selection away from search/list tools. However, it does not explicitly mention when not to use it or name alternative tools, so it falls short of full guideline clarity.

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