Create user.

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

The description reveals that authentication is required, which is a behavioral constraint beyond the openWorldHint annotation. However, it does not disclose what happens after creation, whether it's idempotent, or any side effects beyond the obvious user record creation. Given openWorldHint is set, there's potential for external interactions, but the description doesn't elaborate. So it adds some but not much.

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, short sentence that is directly relevant to the tool's usage. There is no redundancy or wasted words, but it's extremely brief. For a tool with 8 parameters, this brevity might be seen as an under-specification rather than conciseness, as it doesn't even state the basic action.

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?

The tool has 8 optional parameters, no output schema, and only an openWorldHint annotation. The description provides only an authentication prerequisite. It lacks information about required credentials, what fields are needed, behavior on success/failure, differences from bulk creation, or any side effects. This is inadequate for an agent to decide when to invoke it.

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 has 8 parameters with only 13% having descriptions, and the description provides no parameter information whatsoever. Since the schema coverage is low, the description should compensate, but it doesn't. All field semantics rely solely on names and examples, so the description adds no value here.

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 tool name and title clearly indicate it creates a user. The description, while not restating the action, adds a necessary constraint (logged-in requirement), and the action is distinct from sibling tools like update_user, delete_user, and create_users_with_list_input. This makes it easy for an agent to identify when this tool is the right one for creating a single user.

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 states a clear prerequisite: only the logged-in user can perform this action. This tells the agent to use this tool only when there is a logged-in user, but it doesn't provide guidance on when to use create_user vs alternatives like create_users_with_list_input, which serves bulk creation, or update_user. So there's partial context but no comparative guidance.

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