list_usd_variant_sets

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds genuine context beyond them: it reports the return shape (prim_path, names, selections, count) and warns that the selections map may be empty when no selection is authored, which compensates for the absent output schema.

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?

Two compact sentences: the core purpose leads, the selection-edge-case follows, and the return shape is given in a single terse block. Nothing is redundant and the important scoping constraint is front-loaded.

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 read-only list tool whose annotations carry the safety profile, this covers purpose, return shape, and the empty-selection edge case. The only gap is that it doesn't clarify stage resolution when stage_name is omitted, which is a minor omission for a 2-param 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 description coverage is 100%, so prim_path and stage_name are already documented in the schema. The description adds no extra meaning about parameters, such as what happens when stage_name is omitted; baseline 3 applies when the schema does the heavy lifting.

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 and resource ('List every variant set authored on a prim') and adds scope detail about the current selection. It is naturally distinguishable from the singular get_usd_variant_set_info and the add/set siblings by its plural listing semantics, but it never names an alternative explicitly, so it falls short of the 5 bar for sibling differentiation.

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 only implied: an agent can infer it is for inspecting all variant sets on a given prim. There is no statement of when to prefer this over get_usd_variant_set_info, and no note about prerequisites or when the list would be empty.

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