Add fixtures to an existing lighting look while preserving current fixtures and channel values, with optional overwrite for existing fixture data.
Safely add fixtures to a look without affecting existing fixtures
| Name | Required | Description | Default |
|---|---|---|---|
| lookId | Yes | Look ID to add fixtures to | |
| fixtureValues | Yes | Fixtures to add to the look | |
| overwriteExisting | No | Whether to overwrite existing fixture values |
Changes observed during successful MCP inspections.
v1.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It hints at safe/additive behavior ('without affecting existing fixtures'), but there is a tension with the schema's overwriteExisting flag, and it says nothing about permissions, whether added fixtures are appended or merged, or ordering effects.
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, tight sentence with the key scoping qualifier front-loaded and no wasted words.
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 mutation tool with no annotations and no output schema, the description is too thin: it does not clarify the effect of overwriteExisting, the return value, or how it differs from the many sibling look-mutation tools.
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 the schema already documents all three parameters including overwriteExisting and the nested channel values. The description's 'without affecting existing fixtures' loosely maps to the overwriteExisting default, but adds no syntax or format detail beyond the schema, so baseline 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 specific verb ('add') and resource ('fixtures to a look') with a clear scope qualifier ('without affecting existing fixtures'). However, it does not distinguish itself from close siblings such as ensure_fixtures_in_look, copy_fixtures_to_looks, or update_look, so an agent must still infer which tool applies.
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?
There is no explicit when-to-use or when-not-to-use guidance and no mention of alternatives. With several overlapping siblings (ensure_fixtures_in_look, copy_fixtures_to_looks, remove_fixtures_from_look) present, the absence of routing guidance is a real gap.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.