Get entity state

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description adds genuinely new behavior: values are fetched fresh from Home Assistant rather than cached, and attributes are a filtered subset rather than the raw attribute dict. It does not say what happens when an entity_id is unknown, which is the one remaining behavioral gap.

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?

Two short sentences, front-loaded with the core purpose and followed by meaningful qualifications about freshness and attribute filtering. Slightly padded by the parenthetical climate example, but nothing is genuinely wasteful.

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 structure needn't be described; the description instead covers the two things the schema cannot express, data freshness and attribute filtering. Combined with readOnly annotations, that is sufficient for an agent to call this 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?

Only one parameter and schema coverage is 100%; the schema already carries the pattern, example ('climate.hvac') and the search_entities discovery hint. The description adds nothing parameter-specific, so baseline 3 applies.

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 ('Get'), resource ('live state of one entity') and the payload contents (area, device, relevant attributes). It is clearly narrower in scope than sibling tools like search_entities and list_areas, though it never names those siblings to contrast 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?

Usage is only implied: it tells you the state is read fresh and attributes are domain-filtered, so an agent can infer it is for inspecting a known entity. There is no explicit 'use this instead of X when Y' guidance, and the pointer to search_entities lives only in the schema description, not here.

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