viewport_light

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

Annotations already declare destructiveHint=false and openWorldHint=false, but the description adds genuinely new context: which action is a pure read (get returns current mode, available modes, and scene lights), that set mutates state, and that set_camera_light is a legacy path. The mutation scope and legacy status are exactly the kind of extra detail annotations can't express.

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?

Front-loaded one-line purpose followed by a scannable action list and a troubleshooting hint. The mode enumeration partially duplicates the schema's mode description, but it earns its place by being more complete than the schema's examples. Minor redundancy keeps it from a 5.

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 3-parameter tool with full schema coverage, an output schema, and safety annotations, the description covers the remaining gaps: action semantics, mode vocabulary, legacy handling, and the practical workflow that motivates calling it. Nothing an agent needs to invoke it correctly is missing.

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 coverage is 100%, so baseline would be 3, but the description adds meaning beyond the schema by enumerating the full set of valid mode values, including light rigs ("Default", "Colored Lights", "Grey Studio") that the schema only gestures at with 'e.g.' It also clarifies that mode applies to "set" and enabled applies to "set_camera_light", reinforcing the action/parameter coupling.

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?

Names a specific verb pair (query/control) and a specific resource (viewport lighting mode), which is clearly distinct from siblings like set_material, set_visibility, or set_camera. It doesn't explicitly disambiguate against those siblings, but the resource is narrow and unambiguous enough that no confusion arises.

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?

Gives a concrete trigger scenario: when capture_viewport returns a black image, use this tool to check/change lighting and then recapture. It also explains what each of the three actions is for. It stops short of stating when not to use it (e.g. lighting vs. exposure or camera clipping), so it falls short of a 5.

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