Create a Home Assistant user

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

With annotations covering the safety profile, the description still adds substantial context beyond them: the account is a standing entity independent of the creating API key, deleting the token does not remove the user, admin grants owner-equivalent control, and the call requires the ha:config permission. These are real behavioral traits not present in the structured fields.

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 critical fact (no login yet) and the follow-up step are front-loaded, and the persistence warning is bolded for emphasis. Slightly verbose in places ('or they exist but cannot sign in' is an awkward restatement), but nothing is wasted.

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 creation tool with no output schema, the description covers what is produced (an account with no credentials), how to finish the job, the persistence semantics, and the required permission. An agent has everything needed to call it correctly.

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?

Schema coverage is 100%, so the baseline is 3, but the description adds meaning to 'role' by warning that 'admin' is equivalent to the owner and that the choice should be deliberate. It does not elaborate on name or local_only, but those are already well documented in the schema.

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?

States a specific verb and resource ('Create a new Home Assistant user') and immediately scopes it: the account has no login yet. It also distinguishes itself from ha_set_user_credentials and ha_delete_user by explaining the two-step credential flow and that the user persists after token deletion.

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 tells the agent to call ha_set_user_credentials afterwards to make the account usable, and gives guidance on choosing 'role'. It lacks an explicit when-not or a comparison against alternatives like ha_provision_service_login, but the sequencing guidance is clear and actionable.

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