set_material_instance_param_override

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

Annotations already declare destructiveHint, idempotentHint, and readOnlyHint=false, but the description adds real value beyond them: it explains that bOverride=false reverts to the parent value, that UpdateMaterialInstance runs and the change persists, that success=false is returned when the parameter is missing, and that it is editor-only. That is meaningful operational context.

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 core constraint (what true vs false does) is front-loaded, and the return-shape block earns its place because no output schema exists. It is dense but every sentence carries information; no filler.

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, editor-only tool with no output schema, the description covers the side effects (UpdateMaterialInstance + persist), the failure mode (success=false on missing parameter), the environment restriction (editor-only), and an explicit return shape. Nothing an agent needs to call it correctly is missing.

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%, so both the boolean override and the association enum are already documented in the schema. The description largely restates the override semantics and adds no format or default detail for association beyond what the schema already provides. 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 (toggle the override flag) and precise resource (a per-parameter override on a Material Instance Constant), even clarifying it spans all 11 parameter types including static switch. It does not name the near-siblings set_material_instance_param or get_material_instance_param_overridden, so differentiation must be inferred, but the scope is unambiguous.

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 bOverride=true/false semantics imply when you would choose the tool (enabling or reverting an override), but there is no explicit when-to-use, prerequisite, or comparison against set_material_instance_param/set_material_instance_static_switch. Usage is implied rather than stated.

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