ha_get_history

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

No annotations are provided, so the description carries the full burden. It discloses that 'since' expects an ISO time and that entity filtering is optional, but it omits critical behavioral details: the response format, what 'end' and 'minimal_response' do, whether all entities are returned if entity_id is omitted, and any limitations on result size. The read-only nature is only implied by the verb 'Fetch', not explicitly stated.

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 a single sentence of only 12 words and is efficiently front-loaded with the action and key parameters. However, it is too terse for a tool with four parameters and no annotations, crossing from conciseness into under-specification.

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?

With four parameters, no annotations, and no output schema, the description omits crucial context: the meaning of 'end', the effect of 'minimal_response', the default scope when entity_id is absent, and the structure of the return value. An agent would lack sufficient information to use this tool correctly without external knowledge.

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%, so the description must compensate. It explains 'since' as an ISO time and 'entity_id' as an optional filter, covering two of four parameters. However, 'end' and 'minimal_response' are left completely undefined, and the description does not provide enough detail to fully understand expected values or behaviors.

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 uses the specific verb 'Fetch' and identifies the resource as 'history', with clear qualifiers: 'since an ISO time' and 'optionally for an entity'. This distinguishes it from siblings like ha_get_state (current state) and ha_list_states (all states). A minor gap is not specifying the exact nature of the history (e.g., state changes), but the purpose is largely unambiguous.

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 explicit guidance on when to use this tool versus alternatives like ha_get_state or ha_get_logbook. The intended usage is implied by the tool's name and description (fetch historical states), but no alternative tools are mentioned, nor are exclusions or prerequisites stated.

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