set_usd_prim_metadata

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

Annotations already declare the safety profile (destructiveHint=true, idempotentHint=true, readOnlyHint=false), so the bar is lower, yet the description still adds real behavioral context beyond them: "Not saved to disk" (in-memory only), the edit-target scope, and the failure mode where a value type mismatch yields set=false. It does not explain what is destroyed or permission/undo implications.

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 in the first sentence, followed by failure-mode, persistence, and return-shape notes. It is dense but every sentence carries distinct information; a slight compression could still tighten it, but nothing is wasted.

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 full schema coverage, concrete annotations, and no separate output schema, the description supplies the return shape ({ set, key, value }), persistence caveat, and failure semantics needed to call it correctly. The main gap is the lack of sibling routing/disambiguation against the single-field metadata setters, which moderately limits completeness.

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 documents key, value, prim_path, and stage_name thoroughly (including the type/value scalar format). The description's parameter-relevant content (type-mismatch causing set=false, echoed converted value) is largely behavioral and is credited under transparency, so 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?

The description gives a specific verb+resource ("Author one metadata field ... on an existing prim of a registered USD stage") and names concrete example fields, so the agent knows exactly what the tool operates on. It does not, however, differentiate itself from the more specific sibling setters that also write prim metadata (set_usd_prim_display_name, set_usd_prim_active, set_usd_prim_type, set_usd_prim_specifier, set_usd_prim_instanceable), leaving a subtle overlap unresolved.

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?

Usage is implied rather than stated: it must be an existing prim on a registered stage, written at the current edit target. There is no explicit when-to-use vs when-to-use-an-alternative guidance, and notably no routing to the dedicated sibling tools for specific metadata fields like display name or active state.

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