override_usd_prim

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

Annotations cover safety (readOnlyHint=false, destructiveHint=false, idempotentHint=true), and the description adds genuinely non-structural behavior: an existing prim is returned untouched with already_existed true and no specifier reported, specifier Over is only returned for a newly authored over, is_valid=false means USD refused the authoring, missing stage/bad path is an error, and changes are in-memory only. This is rich, non-obvious context beyond the annotations.

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?

Front-loaded with the primary action and scope, then siblings, then edge-case semantics and the return shape. Dense but every clause carries information an agent needs; only minor redundancy (e.g., re-explaining already_existed).

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?

There is no output schema, so the description supplies the return contract ({prim_path, is_valid, already_existed, specifier?}) plus the conditions under which specifier is absent or present, the error semantics, the in-memory/persistence behavior, and the sibling delegation paths. Nothing an agent needs to call this correctly 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 coverage is 100%, so the schema already documents both parameters well; baseline would be 3. The description adds meaning the schema lacks by describing the semantics of prim_path (authoring an over with ancestors for missing paths, use of the current edit target) and clarifying that stage_name resolution includes the USD cache and root layer identifier ending, which goes beyond the schema's wording.

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 (author an over) and resource (prim at prim_path on a registered USD stage), and explicitly distinguishes from siblings by naming define_usd_prim (typed def) and set_usd_prim_specifier (change specifier of existing prim). An agent can select this tool over its USD siblings without opening any 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?

Explicit when-to-use (add opinions to a prim without defining it) and when-not (delegate to define_usd_prim for a typed def, set_usd_prim_specifier to change an existing prim's specifier). Also states that save_usd_stage writes in-memory changes, which is the routing condition between authoring and persisting.

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