Updates an existing sky layer to a dawn, noon, golden-hour, dusk, or night preset by changing zenith, horizon, and haze colors.
Update an existing sky layer to a time-of-day preset, changing zenith, horizon, and haze colors.
| Name | Required | Description | Default |
|---|---|---|---|
| layerId | Yes | Target sky layer ID. | |
| timeOfDay | Yes | Time-of-day preset to apply. |
Changes observed during successful MCP inspections.
v0.5.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It says which colors are changed, but does not state whether the update overwrites custom values, whether the change is reversible, or what permissions or layer conditions are required. For a mutation tool with zero annotation coverage, this is a significant gap.
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 waste. The operation, target resource, and visual effect are all front-loaded.
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?
The core operation is clear and the schema fully documents both required parameters. However, because this is a mutation with no annotations or output schema, the description should say more about overwrite behavior, reversibility, and valid layer preconditions. It is adequate but has clear gaps.
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 both parameters are already documented with a clear enum for timeOfDay. The description adds useful meaning by explaining that the preset affects zenith, horizon, and haze colors, but it does not map individual presets to outcomes or add syntax details beyond the schema. Baseline 3 is appropriate when the schema does the heavy lifting.
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 gives a specific verb and resource: update an existing sky layer with a time-of-day preset. It also lists the affected color properties (zenith, horizon, haze), making the purpose unambiguous. It does not explicitly name or differentiate sibling tools such as design_add_sky, so it falls short of a 5.
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 'existing sky layer' implies the tool should be used when a sky layer already exists, but the description does not state when to choose this over alternatives. There are no explicit exclusions, prerequisites, or recommended alternatives. Usage is therefore only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.