ue_set_time_of_day

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

Annotations indicate idempotentHint=true and destructiveHint=false. The description adds behavioral context: it drives multiple lighting properties, builds/reuses the sky rig, and recaptures. This goes beyond the annotations by explaining side effects without contradiction.

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 two sentences long, front-loaded with the primary action and followed by key effects and technical detail. Every word contributes value; there is no redundancy or verbosity.

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?

Despite having one parameter and an output schema (not shown), the description covers the parameter's effect and the tool's overall behavior (sky rig reuse). It could mention prerequisites (e.g., sky atmosphere setup) but remains adequate for a focused tool with idempotent annotation.

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?

The input schema provides no description for the 'hour' parameter (0% coverage). The description compensates by specifying the valid range 0-24 and explaining that it drives sun elevation, compass azimuth, colour temperature, and intensity. This adds meaning beyond the schema's type and default.

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 clearly states the tool sets the time of day and specifies the hour range 0-24. It enumerates the effects (sun elevation, azimuth, colour temperature, intensity) and mentions sky rig reuse, making the purpose unambiguous and distinct from sibling tools like ue_setup_sky_atmosphere.

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 description does not provide explicit guidance on when to use this tool versus alternatives. While the purpose is clear, there is no mention of prerequisites or conditions (e.g., requiring ue_setup_sky_atmosphere first), nor comparison to sibling tools that might adjust lighting differently.

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