set_material_domain

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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=true, so the mutation profile is covered. The description adds one genuinely new behavioral fact beyond the annotations: that the material is recompiled as a side effect, and it lists the returned fields (previous_domain, domain_set, etc.) since no output schema exists. It omits failure modes and permission needs.

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?

Short overall and the core action is front-loaded, but the structure is broken: the enum fragment "'LightFunction', 'Volume'" hangs mid-sentence with no label, and the Returns block is appended as raw text. Every element earns its place, but the ordering and formatting are poor.

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?

With no output schema, documenting the return fields is a necessary and useful addition, and the recompile side effect is disclosed. However, nothing is said about prerequisites (material vs. material instance), whether recompilation is synchronous, or failure behavior for an invalid domain — gaps for a 2-param destructive write tool.

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 baseline is 3, but the description contributes real value: the schema's 'domain' description is truncated mid-list ('Surface', 'PostProcess', 'UI', 'DeferredDecal',) and the description supplies the missing allowed values 'LightFunction' and 'Volume'. The dangling placement makes the completion hard to read, but it does add semantics beyond the schema.

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+resource ('Set a material's domain') plus the additional action ('and recompile it'), so an agent knows this mutates a material's EMaterialDomain. It does not name or differentiate against any sibling tool, though no sibling competes for this operation.

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 alternatives are mentioned. The agent gets no signal about how this differs from the many other material-mutation tools (compile_material, set_material_instance_parent, etc.) or when a domain change is appropriate.

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