set_decal_material

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

Annotations already declare destructiveHint=true, idempotentHint=true and readOnlyHint=false, so the safety profile is covered. The description adds the return shape (actor_label, material_path), which is useful since no output schema exists, but it does not explain that the prior material is replaced or what happens with an invalid actor label.

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 tight sentences: the action first, then the return shape. Every clause carries information and there is no padding.

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?

Adequate for a small two-required-param mutation: annotations cover safety, the description supplies the return shape in lieu of an output schema. It still omits preconditions (existing decal actor, valid material path) and failure behavior, which matter for a destructive write.

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 both parameters are already documented, and the baseline is 3. The description reinforces semantics by naming the target (named DecalActor) and the accepted asset type (UMaterialInterface), but adds no format or syntax detail 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 precise verb+resource ('Assign a UMaterialInterface to the UDecalComponent on a named DecalActor'), which clearly distinguishes it from siblings like set_decal_color or set_decal_size. It does not name those siblings explicitly, so differentiation is inferable rather than stated.

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 mention of prerequisites (the DecalActor must already exist), and no routing to alternatives such as set_decal_color or spawn_decal_actor. The agent must infer usage entirely from the verb.

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