set_material_function_output_props

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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=true. The description still adds real value by disclosing that ValidateName is re-run when output_name changes and by listing the returned fields, though it never explains the destructiveHint=true side (e.g. what state is affected by renaming a pin).

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?

Three tight sentences: the action and locator come first, the update semantics second, and the return shape last. No filler, and since there is no output schema the return signature earns its space.

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?

For a mutating, non-read-only tool with no output schema, the definition covers the mutation semantics, the validation side effect, and return fields. It is thin only on the destructive/rename consequences that the annotations flag as destructiveHint=true.

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% and all five parameters are documented in the schema, including the '/Game/...' path format example. The description only reinforces node_id as the locator and adds the ValidateName trigger for output_name, so baseline 3 is appropriate.

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 properties) and resource (UMaterialExpressionFunctionOutput), including the lookup key (node_id) and the fact that the node must already exist. It clearly separates itself from add_material_function_output and set_material_function_input_props without opening either 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?

'Partial update (idempotent)' tells the agent it may send only the fields it wants changed, and 'existing' implies the output node must be created first via add_material_function_output. It stops short of explicitly naming the create/delete siblings or stating when-not-to-use.

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