set_material_properties

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It usefully discloses that the tool 'fails clearly' on texture-driven properties and suggests a remedy, but it does not explain key behaviors such as what happens when a material name does not exist, whether null/omitted parameters leave existing values unchanged, or what the return/error shape is.

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 two sentences with no filler: the action is stated first, and the behavior note adds genuinely useful information. It is well front-loaded and every sentence 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?

Given 14 parameters, no annotations, and no output schema, the description is incomplete. It covers one edge case but omits crucial operational details such as whether the target material must already use Principled BSDF, whether omitted properties are preserved, and how errors are reported. An agent would likely need to rely on trial and error.

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 only 21%, and the description does not compensate by explaining any of the 14 parameters. It neither clarifies that unset/null properties are left unchanged nor gives guidance on how values like base_color or emission_color should be formatted beyond what the schema already states. The schema's names and ranges must do all the work.

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 action ('Update') on a specific resource ('existing material') and narrows the scope to 'Principled BSDF properties.' This distinguishes it from siblings like create_material, assign_material, and get_material, though it does not explicitly name or contrast those 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?

The description gives explicit guidance for one important case: if a property is driven by a texture node, edit the node instead or disconnect it first. This provides a clear exclusion and remediation path, but it does not broadly explain when to choose this tool over related node-editing tools like set_node_inputs.

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