list_users

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

With no annotations, the description carries the full burden of behavioral disclosure. It states 'Operator only' but doesn't explain what that means (e.g., role-based access), nor does it describe the return format, pagination, or side effects. The parenthetical about the opted-in list adds a bit of context but is insufficient.

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 is front-loaded with the key permission constraint. It efficiently conveys the main points without unnecessary 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?

For a no-parameter tool with no annotations and no output schema, the description should do more to clarify the return data and usage. It mentions users, consents, and interest profiles, but lacks details on structure, operator context, and how it relates to siblings. The brief parenthetical is not enough.

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?

There are zero parameters, so the baseline score is 4. The description doesn't need to explain parameters, and it correctly focuses on the output instead.

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 uses a noun phrase rather than a clear verb+resource, but the tool name 'list_users' carries the verb. It mentions registered users, consents, and interest profiles, giving some sense of what data is returned. However, it doesn't clarify if this is purely a list operation or includes nested data, and it doesn't differentiate from siblings like 'my_data' or 'consent'.

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 only guidance is 'Operator only', which indicates a permission requirement but not when or why to use this tool. There's no mention of alternatives or context for invocation, leaving the agent to infer usage.

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