get_material_instance_params

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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower, yet the description adds high-value behavioral context: it never returns static switches and hides un-overridden parent parameters, explaining that such parameters still inherit the parent value. It also explains the practical consequence – an instance can look green while a parent switch disables a layer.

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 definition is front-loaded: the first sentence delivers the core distinction before any caveats. The subsequent sections ('Two omissions to keep in mind' and the sibling routing sentence) each address a genuine semantic trap rather than padding, and the return shape is appended compactly.

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 supplies the return structure explicitly, including counts and field shapes. Combined with the safety annotations and full parameter schema, an agent has everything needed to select and invoke this tool correctly.

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% and the single material_instance_path parameter is fully documented in the schema as a content path to a UMaterialInstanceConstant. The description implies the same input but adds no syntax, format, or edge-case detail beyond the schema, so the baseline of 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?

The first sentence states a specific verb (List), resource (material instance parameter values), and scope (actually OVERRIDDEN scalars, vectors, textures). It explicitly distinguishes this from the broader sibling get_material_all_parameters and from the static-switch tools, so an agent can route correctly without opening schemas.

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?

It gives explicit when-to-use (what has been calibrated here) and when-not (what can I tune), plus named alternatives for both gaps: get_material_all_parameters for the full tunable contract and get_material_static_switch_parameters / get_material_instance_static_switch for switches. Nothing relevant 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.