set_usd_attribute_value

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

Annotations already declare the mutation profile (readOnly=false, destructive=true, idempotent=true), so the bar is lower. The description adds two genuinely useful facts beyond that: auto-creation of the attribute when absent, and the exact return payload shape, which matters because there is no output schema. It does not warn that an existing attribute value is overwritten (the destructive aspect).

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?

One short purpose sentence plus a single-line return contract — every element earns its place and the purpose is front-loaded. Slightly terse, but 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 USD tool with annotations covering safety and a fully documented 6-parameter schema, the description supplies the missing return-shape information (no output schema exists) and the create-if-missing behavior. The remaining gap — that setting overwrites an existing authored value, and that type_name is required on creation — is partly covered by the schema.

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 the schema already explains value, type_name, prim_path, stage_name and time in detail. The description adds nothing parameter-specific beyond mirroring the return field names; 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?

Names a specific verb (author/set) and resource (a value on a USD attribute) and adds the important scope note that the attribute is created if missing. This implicitly separates it from create_usd_attribute and get_usd_attribute_value, though it never names a sibling outright.

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 parenthetical '(creating it if missing)' is the only usage steering: it implies the agent need not call create_usd_attribute first. There is no explicit when-to-use statement, no condition for preferring this over set_usd_prim_metadata / create_usd_attribute / set_usd_prim_type, and no exclusions.

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