set_volumetric_cloud_properties

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

Annotations already carry the safety profile (destructive/idempotent/readOnly), so the bar is lower, and the description adds genuinely useful behavior: only supplied fields are mutated, applied_count reflects that, and the reply reads every property back. It does not explain what happens on an invalid actor_name or how destructiveHint manifests (e.g. overwriting existing values).

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?

Two tightly packed sentences plus a Returns line, with the core action front-loaded. Slightly dense in the property enumeration, but no sentence is wasted and the inline 'Returns:' block is useful given there is no output schema.

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 13-parameter mutation tool with no output schema, the description covers the action, the patch semantics, the units of the tricky parameter, and the exact response shape. It is nearly complete; only error/failure behavior remains unaddressed.

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 the schema already documents every parameter including units and the [R,G,B] FColor byte range. The description restates ground_albedo semantics and the opt-in nature of the fields, adding marginal value but nothing the schema lacks; 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 and resource ('Set the properties of a VolumetricCloud actor's UVolumetricCloudComponent') and enumerates the property families covered (layer/planet geometry, ground albedo, tracing distances and sample counts). An agent can distinguish this from the get_* sibling without opening the schema, though no sibling is named explicitly.

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 implies usage context via the partial-update note ('Only the supplied fields change'), which tells the agent it can send a minimal patch rather than a full state. It never states when to prefer this over get_volumetric_cloud_properties or spawn_volumetric_cloud, nor any prerequisite like actor existence.

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