ha_get_stateRetrieve the current state and attributes of a Home Assistant entity by its entity ID, such as sensor.kitchen_temperature.
Current state and attributes of a single entity. Args: entityId (e.g. sensor.kitchen_temperature).
| Name | Required | Description | Default |
|---|---|---|---|
| entityId | Yes | Entity id, e.g. "light.study_light" |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety and idempotency profile is fully covered. The description adds only that the response contains state plus attributes; it says nothing about behavior for an unknown/removed entity, availability, or value formatting, so it is adequate but not rich.
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 tight sentences with no filler, and the definition of what is returned is front-loaded. The inline 'Args:' stub is slightly mechanical but costs almost nothing in length.
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, fully-annotated read tool with no output schema, the description usefully declares what comes back (state and attributes), which is the main missing structured information. Only edge-case behavior (unknown entity, unavailable state) is absent, which is a minor gap at this complexity.
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 parameter carries its own description with an example. The description merely repeats an example ('sensor.kitchen_temperature') without adding domain/format rules (e.g. that the domain prefix determines behavior), so the baseline 3 is correct.
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 names the resource (one entity) and the data returned (current state and attributes), which is specific enough to distinguish it from ha_list_states at a glance. It lacks an explicit verb ('Get' appears only in the tool name) and never names the sibling it contrasts with, so it stops short of a 5.
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 when-to-use guidance, no prerequisites, and no reference to alternatives such as ha_list_states for bulk reads or ha_get_history for past values. The phrase 'a single entity' weakly implies the alternative, but the agent must infer it entirely on its own.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.