set_actor_material

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

Annotations cover the safety profile (not read-only, not open-world, idempotent, destructive), but the description adds substantial context beyond them: exactly what is left untouched (mesh asset, other slots), error conditions (missing actor/mesh component/material, out-of-range slot_index), and side effects (one undo step, level marked dirty but not saved). This is rich disclosure the structured fields do not carry.

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?

Front-loaded with the action and scope, and there is essentially no filler — every clause conveys a constraint, side effect, or routing hint. It is dense with several concerns packed together, which slightly taxes scanning, but nothing is wasted.

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?

No output schema exists, yet the description supplies the return shape ({ actor_name, material, slot_index }). Combined with the documented error cases, undo/dirty semantics, and component targeting, an agent has everything needed to invoke and interpret the call.

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 baseline is 3, but the description adds real meaning: actor_name resolves by name or label, and slot_index is constrained to the resolved component's slot range (refused if outside), which clarifies which component the index applies to. It adds interpretation beyond the raw schema strings.

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 (Set) plus resource (component-level override material on one slot of an editor-world actor) and even specifies the target component resolution (first StaticMeshComponent, else first other mesh component). It names two siblings it is not, so an agent can separate it from set_static_mesh_material_slot and create_dynamic_material_on_actor without opening schemas.

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?

Explicitly routes the agent: 'For the mesh asset use set_static_mesh_material_slot; for a tweakable runtime copy, create_dynamic_material_on_actor.' Both alternatives and the condition that selects each are given, leaving nothing to inference.

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