material_instance_create

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

No annotations are provided, so the description carries the full burden. It discloses the side effect 'Saves the instance', but does not detail overwrite behavior, error handling, or requirements such as the parent material being valid, which are relevant for a mutating create operation.

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 a single, clear sentence that front-loads the core action and includes the key optional overrides. There is no filler or redundancy.

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 and full parameter documentation, the description adequately covers the main action and the saving side effect. However, it omits important context like overwrite semantics and failure conditions, leaving some gaps for an agent deciding whether to invoke this tool.

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%—all six parameters have descriptions. The description's 'optional scalar/vector/texture parameter overrides' maps to the corresponding params but adds no extra detail beyond what the schema already states.

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 uses the specific verb 'Create' with a clear resource 'MaterialInstanceConstant' and mentions optional parameter overrides. It distinguishes from siblings like material_create (creates a material, not an instance) and material_instance_set_params (sets parameters on an existing instance).

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 action 'Create' implies the use case (creating a new material instance), but the description does not explicitly mention alternatives or when not to use it. Sibling tools exist that could be confused, but no comparisons or exclusions are provided.

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