Create area

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

Annotations already flag readOnly=false, idempotent=false, destructive=false, but the description adds the concrete consequence: HA assigns area_id automatically with no way to request one, so calling twice with the same name produces two distinct areas. That operationalizes the non-idempotent hint in a way the annotation cannot, and notes the return payload.

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?

Front-loaded with the core action, then structured into mechanism, when-to-use, when-not-to-use, and return shape. Every sentence carries distinct information; nothing is padding.

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 single-parameter creation tool, the description covers mechanism, duplication risk, alternative tools, and return contents. The output schema already exists, so the brief returns line is a convenience rather than a gap.

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?

Only one parameter with 100% schema description coverage ('Display name for the new area, e.g. Kitchen'), so the schema already carries the semantics. The description restates that `name` is what is passed to the WS call but adds no format constraints or edge cases. Baseline 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?

States a specific verb and resource ('Create a new Home Assistant area') and goes further by naming the underlying WebSocket call (`config/area_registry/create`). An agent knows exactly what entity type is produced and how it is stored, distinct from siblings like areas_update_area or areas_delete_area.

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?

Uses explicit 'Use when' / 'Not for' framing, naming the condition for use (need a new area to assign devices, entities, or labels) and the alternative for the excluded case (`areas_update_area` for renames, icon, floor, aliases). Nothing is left to inference.

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