Set Zone

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

Annotations declare destructiveHint: true, and the description confirms modification behavior. It adds specific constraints: only specified fields change on update, defaults for radius and passive on create, and the home zone restriction. This goes beyond the annotation's general destructiveness hint.

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 concise and well-structured: a clear first sentence, followed by bullet-like paragraphs summarizing create vs update, then examples, and a final note. Every sentence adds value, with no redundant information.

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?

Given the tool's complexity (create/update, 7 params) and the presence of an output schema, the description is fairly complete. It covers key behavioral aspects, required fields, defaults, and a notable restriction. Lacks details on error handling or edge cases like invalid coordinates, but schema validation likely covers that.

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?

Input schema covers all 7 parameters with descriptions (100% coverage). The description adds semantic value by clarifying which parameters are required for create (name, latitude, longitude) and showing usage via examples. It also states default values (radius 100, passive False) that are not explicitly 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?

The description clearly states the tool's purpose as 'Create or update a Home Assistant zone', which is a specific verb+resource. It distinguishes itself from sibling tools like ha_get_zone (read) and ha_remove_zone (delete) by explicitly covering both creation and update operations.

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 provides explicit guidance on when to use each mode: omit zone_id for create, provide for update. It also notes the limitation that the 'home' zone cannot be modified. Examples illustrate typical usage, and it references sibling tool ha_get_zone for finding zone IDs. However, it does not explicitly compare to alternatives like ha_remove_zone for deletion, though that is implied.

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