create_material_function

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

Annotations already declare not-read-only, not-open-world, idempotent, non-destructive. The description goes further: it explains what idempotency concretely means (existing function returned untouched with already_exists=true), that a conflicting asset class is an error, and that the asset is saved. That specificity is real value beyond the annotations, though save-failure/permission behavior is unstated.

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 action is front-loaded and the idempotency clause is efficient. There is mild redundancy: return fields are summarized in prose ('Returns function_path, num_inputs, num_outputs and saved') and then fully re-listed in the Returns block.

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?

No output schema exists, but the description inlines a complete return shape (function_path, name, package_path, description, num_inputs, num_outputs, created, saved, already_exists) plus error semantics, so an agent knows what to expect. Only edge behavior (auth, failure modes) 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 description coverage is 100%, so all three parameters are documented in the schema, including the Description tooltip semantics and the idempotency note for description. The prose adds 'at package_path/name' but nothing substantive beyond the schema, 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?

States a specific verb+resource (create a UMaterialFunction asset) and pins the location semantics to package_path/name, while naming the sibling creation tools implicitly via distinction (delete_material_function, create_material_function_instance coexist). An agent can tell what this produces and where without opening the schema.

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 states the tool creates and saves the function and describes idempotent behavior, which informs usage, but never says when to prefer this over alternatives (e.g., create_material_function_instance or create_material_function_expression) or any prerequisites. Usage is implied rather than enumerated.

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