Modify an existing lighting look by changing its name, description, or fixture channel values.
Update an existing look with new values
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | Optional new name for the look | |
| lookId | Yes | Look ID to update | |
| description | No | Optional new description for the look | |
| fixtureValues | No | Optional fixture values to update |
Changes observed during successful MCP inspections.
v1.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, yet it only implies mutation. It does not say whether the update is a full replacement of fixture values or a merge, whether omitted fields are preserved, or what permissions are required — a material gap given the adjacent 'update_look_partial' 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?
A single, front-loaded sentence with no filler or repetition. It is efficient, though its brevity borders on under-specification rather than genuinely tight communication.
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 4-parameter mutation tool with no annotations and no output schema, the description is too thin. It omits the full-replace vs partial-update semantics that would let an agent choose correctly over 'update_look_partial' and 'bulk_update_looks'.
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 description coverage is 100%, so every parameter (lookId, name, description, fixtureValues with nested channel offsets/values) is already documented. The description adds no syntax, format, or replacement semantics beyond the schema, so the baseline of 3 applies.
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?
States a clear verb (Update) and resource (look) with a mutating scope, but 'with new values' is vague about what can change and the description never distinguishes itself from the sibling 'update_look_partial' or the bulk variants. An agent could not confidently choose between update_look and update_look_partial from this text alone.
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?
No when-to-use guidance, no prerequisites, and no mention of alternatives despite an obvious sibling (update_look_partial) covering similar territory. The agent is left to infer the selection criteria entirely.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.