list_lights

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

No annotations are provided, so the description carries the burden of indicating behavior. 'List... with their current state' conveys a read-only enumeration operation and identifies what the agent can expect. It does not mention pagination or error behavior, but for a simple no-parameter list tool this is acceptable.

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 with no filler. Every word contributes meaning: 'List', 'all lights', 'known to the deCONZ gateway', and 'current state' are all necessary.

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 no-parameter, collection-level list tool with an output schema available, the description fully covers what the tool does and what scope it operates on. No additional context about return values is needed because the output schema handles that.

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 tool has zero parameters and the schema is empty, so there is nothing for the description to add about parameters. The baseline of 4 applies because no parameter documentation is needed.

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 identifies the verb ('List'), the resource ('all lights'), and the scope ('known to the deCONZ gateway') plus what is returned ('current state'). This strongly distinguishes it from sibling tools like get_light (single light) and set_light_state (mutating a light).

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 phrase 'all lights' makes clear this is the enumeration tool, implying use when the agent needs a full collection rather than a single light. It does not explicitly name alternatives or exclusion conditions, but the context is sufficiently clear.

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