Get entities in area

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real value beyond them: it discloses the underlying read path (entity and device registries over WebSocket), the matching rule (own area_id OR device_id of a device assigned to the area), and the limit that an unknown area_id yields an empty list rather than an error. Missing only return-format/pagination detail, which the output schema likely covers.

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-loads the core action, then uses compact labeled sections (Use when / Not for / Returns / Limits). Every sentence carries unique information; nothing restates the name or title.

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 one-parameter read tool with full schema coverage, annotations, and an output schema, the description covers purpose, routing, semantics, and edge-case behavior. Nothing needed to invoke it correctly is missing.

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 description coverage is 100% and the single area_id parameter is fully documented in the schema, including where to obtain it (areas_list_areas). The description adds no syntax or format beyond 'given area', so the baseline 3 applies when the schema does the heavy lifting.

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 (get entity registry rows for an area) and immediately clarifies the scope: direct area members plus entities reached via their device. It explicitly separates itself from areas_get_area_states and snapshot_get_area_snapshot, so the agent can disambiguate without reading any schema.

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?

Contains an explicit 'Use when' clause (need entity registry rows for one area, e.g. before bulk-editing labels/categories) and a 'Not for' clause naming the two siblings to use instead for state values or combined views. When-to-use, when-not, and alternatives are all present.

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