create_ik_rig

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

Annotations already declare idempotentHint and destructiveHint=false, but the description goes well beyond them: it explains the exact branch where an existing rig with a different mesh is loaded, given the mesh and re-saved, and the branches where nothing changes and nothing is saved (already matching mesh, mesh fails to load, engine refuses with skeletal_mesh_set=false). Including the failed-save path (success false, saved=false, save_error) is exactly the kind of mutation detail the agent 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?

Purpose is front-loaded in the first clause, and every following sentence carries behavioral weight (idempotency semantics, defaults, failure handling). It is dense but not padded; the return-value enumeration is justified because there is no output schema to carry it.

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, the description compensates by enumerating the returned fields, and it fully covers mutation and failure behavior. The only gap is that it does not state prerequisites (a valid skeleton or source mesh needing to exist in the project), which an agent would benefit from before calling.

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 description coverage is 100%, so all three parameters are already documented in the schema, including the same default path for skeletal_mesh_path that the description repeats. The description adds no syntax or format detail beyond the schema, so the 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+resource (create a UIKRigDefinition asset) plus the side effect (set its source skeletal mesh) and the save behavior. An agent can identify exactly what this produces, and no sibling tool in the list creates an IK rig definition, so it is unambiguously distinct from create_ik_retargeter or create_control_rig_blueprint.

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 idempotency explanation implicitly tells the agent it need not pre-check for an existing rig, which is useful usage context. However, it never names an alternative or states a when-not condition, and gives no prerequisites (e.g. that a skeleton/skeletal mesh must exist first). Usage is implied rather than instructed.

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