set_niagara_component_color

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

Beyond the annotations (readOnlyHint=false, destructiveHint=true, idempotentHint=true), the description discloses genuinely useful behavior: it resolves the component on the owner actor, calls SetVariableLinearColor, and then reads the value back to verify. That verification step and the resulting 'verified'/'value_read_back' fields are not derivable from annotations or schema. It does not cover failure modes (e.g., what happens if the actor has no Niagara component), which keeps it below 5.

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?

Two tight sentences followed by an explicit return shape; the mutating action is front-loaded and there is no filler. The inline return signature is slightly dense but earns its place since no output schema exists.

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 mutation tool with no output schema, the description compensates well by documenting the exact return object (actor_name, variable_name, variable_type, set, verified, value_read_back). The main remaining gap is the absence of error/precondition behavior for a non-existent component or actor.

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 actor_name, variable_name, and the color array are already fully documented in the schema. The description adds no parameter-level detail beyond what the schema provides, 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?

The description states a specific verb and resource ('Sets a LinearColor override parameter on a spawned Niagara component') and even names the underlying API call. It is clearly distinguishable from the typed siblings (set_niagara_component_float/int/vector), though it never explicitly names them as alternatives.

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 phrase 'on a spawned Niagara component' and the mention that it 'Resolves the UNiagaraComponent on the owner actor', which signals this targets a runtime instance rather than an asset. However, there is no explicit when-to-use guidance versus set_niagara_component_vector, set_niagara_user_parameter, or the other typed setters.

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