add_spline_mesh_component

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

Annotations already declare the safety profile (readOnly=false, destructive=false, idempotent=false), so the description does not need to restate them. It adds substantial value beyond them by disclosing the internal construction sequence (NewObject + SetStaticMesh + RegisterComponent + AddInstanceComponent + attach to root, CreationMethod=Instance) and the deformation behavior (tangent = end - start).

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 core action and effect. The enumerated internal steps are dense but informative and the return block is compact. Slightly verbose, but every clause carries operational meaning.

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, but the description supplies the return shape explicitly, and parameters are fully covered by the schema. For a mutation tool with annotations, the remaining gap is only that it does not emphasize repeat calls creating duplicate components (implied by the non-idempotent hint).

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 adds meaning the schema lacks by explaining the relationship between start and end ('tangent = end - start') and that the mesh is deformed straight between them. That is genuine semantic value over the per-field schema descriptions.

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?

Names a specific verb and resource ('Adds a USplineMeshComponent instance to a named editor-world actor'), and the detail that it deforms the mesh from start to end distinguishes it from siblings like add_spline_component or add_static_mesh_socket. An agent can tell exactly what this creates without opening the schema.

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?

Usage is implied by the editor-world actor framing but there is no explicit when-to-use, when-not-to-use, or named alternative (e.g., why use this instead of add_spline_component or add_instanced_static_mesh_component). Context is present but the routing guidance is left to inference.

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