add_set_scalar_parameter_value_node

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

The description discloses the core mutation (adding a node that changes a material parameter at runtime) and gives an example. With no annotations, the burden is higher: it does not mention prerequisites such as an existing dynamic material instance, whether the blueprint graph is dirtied, or whether compilation is needed afterward.

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?

The description is well-organized: purpose and use cases first, followed by parameter details, a KB reference, and an example. It is slightly longer than necessary, and the example omits optional parameters, but every section earns its place.

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?

The description provides good coverage of parameters, use cases, and a KB pointer, and an output schema exists so return values need not be explained. Still, without annotations, operational prerequisites and side effects are under-specified, and the example's dynamic_material_variable mismatch reduces completeness.

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 0%, but the Args section explains all five parameters with meaningful context, including scalar value type, node position format, and parameter name examples. The dynamic_material_variable field is described as a variable name, yet the example passes an asset path, creating some ambiguity.

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?

The description clearly states the tool's action: add a SetScalarParameterValue node to change a material float parameter at runtime. This differentiates it from sibling tools like add_set_vector_parameter_value_node by explicitly naming the scalar/float behavior.

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?

Concrete use cases are given (opacity fade-in, glow intensity, dissolve transitions), making intended usage clear. However, it does not explicitly state when not to use this tool or contrast it with alternatives, so it stops short of a 5.

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