list_lights

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 clearly indicates a non-destructive read operation ('Return a list'), but it does not disclose potential edge cases such as behavior when the scene has no lights, nor does it mention ordering or any side effects. For a simple list tool, this is adequate but lacks explicit reassurance about being safe and side-effect-free.

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, well-structured sentence with no filler. It immediately states the action and resource in a compact form, making it easy for an agent to parse and act on.

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?

Given the tool has no parameters and an output schema is provided, the description fully covers what an agent needs to know. It specifies the exact resource (all light objects) and scope (in the scene), leaving no ambiguity about the tool's behavior. The presence of an output schema handles return format details.

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?

This tool has no parameters; the schema is empty, so schema coverage is trivially 100%. The description adds no parameter information because none is needed. According to the rubric, zero parameters warrant a baseline score of 4, and there is no gap to compensate for.

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 'Return a list of all light objects in the scene' uses a specific verb (return), a specific resource (light objects), and a clear scope (all in the scene). It unambiguously distinguishes this read-only listing tool from siblings like create_light, delete_light, and set_light_property, which perform different actions on lights.

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 usage: if you need to know what lights exist, call this tool. However, it does not explicitly state when to use it over alternatives or mention any exclusions. It lacks any statement like 'Use this to inspect lights before modifying them' or 'This returns all lights, not a filtered subset.' The guidance is entirely implicit.

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