ha_light_on

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states the action and parameters; it does not mention side effects (e.g., updating entity state, requiring a connection to Home Assistant), potential errors, or any state-changing implications beyond the literal 'turn on'. This is minimal for a mutation tool.

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, front-loaded sentence that immediately communicates the tool's purpose. It includes only essential information about parameter options, with no redundant or filler content. Every word serves a purpose.

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 simple tool with a clear schema and no output schema, the description is nearly complete. It specifies the action and available options, and the schema covers all parameter details. It does not explain return values or error behavior, which would be expected in the absence of an output schema, but given the low complexity, this is a minor gap.

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?

The input schema already covers all four parameters with descriptions, so coverage is 100%. The description adds no additional meaning beyond what the schema provides; it merely restates the brightness range and color options. Therefore, the baseline of 3 is appropriate.

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 clearly states the tool's action ('Turn on') and resource ('a Home Assistant light'), with a specific verb and target. It distinguishes itself from the sibling ha_light_off by its explicit on action, and from ha_service by focusing specifically on light turning on.

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?

The description implies when to use the tool (when you want to turn on a light) but does not provide explicit guidance on alternatives or exclusions. It does not mention that ha_light_off should be used for turning off, or that ha_service might be a more general option. This is acceptable for a simple tool but below the explicit level expected for a 4.

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