ha_describe_entity

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds value by listing the returned content categories, but discloses no auth, rate-limit, or failure behavior beyond that; with annotations doing the safety work, this is adequate.

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?

A single front-loaded sentence with no wasted preamble; the one weakness is the trailing clause about 'ready-made settings for a Home Assistant key,' which is slightly convoluted and could be firmer.

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?

An output schema exists, so return values need not be spelled out, and annotations cover the read-only nature. The remaining gaps are the undocumented parameter format and the absence of any when-to-use routing against ha_search/ha_call_service, which a 1-param tool of this kind should still provide.

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 0% for the single required entity_id, and the description does not compensate – it never states the expected format (e.g. domain.object_id) or how to obtain a valid identifier. The schema therefore leaves the only parameter undefined.

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 enumerates exactly what a caller receives for one entity: state, attributes, area, domain services, and prebuilt settings. That is specific enough to distinguish it from ha_search (discovery) and ha_call_service (mutation), though it never names those siblings explicitly.

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?

There is no statement of when to reach for this tool versus ha_search or ha_call_service, and no note that an entity_id is typically obtained from ha_search first. Usage must be inferred entirely from the name.

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