set_light

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

The annotations already declare that this is a non-read-only, idempotent, non-destructive mutation. The description adds crucial context beyond them: changes are browser-only, are not persisted to source code, are lost on reload, appear in pending_changes, and can be undone with revert_changes.

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 first sentence front-loads the critical live-preview and persistence warning, and the second sentence compactly enumerates the adjustable properties. Every sentence earns its place with no redundant restatement.

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 output schema, the description covers the essential behavioral traits an agent needs: browser-only scope, persistence loss, pending-change recording, and undoability. The remaining parameter identification is adequately handled by the schema.

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 71%, leaving intensity and castShadow without schema descriptions. The description compensates by naming those fields, and it adds useful semantics for groundColor by noting it applies to HemisphereLight.

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 states a precise verb and resource: it changes a light and lists the specific light properties that can be modified. This distinguishes it from siblings such as set_object_transform, set_material_property, or set_shadow, which target different scene entities.

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?

It clearly frames the tool as a live-preview-only operation whose effects are not saved and are lost on reload, which implies when to use it. However, it does not explicitly compare this tool with alternatives or state when not to use it.

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