rig_physics

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that the result is runtime secondary motion with no baked keys, and explains the taper effect down a chain. However, it omits mutation semantics, such as whether existing constraints are overwritten, permission requirements, reversibility, or side effects.

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 description is compact and front-loads the core concept before listing presets and overrides. Every sentence carries information, though the phrasing is slightly cryptic and could be clearer without adding length.

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 5-parameter mutation tool with 0% schema description coverage, no annotations, and no output schema, the description is incomplete. It omits explanations for required parameters 'bones' and 'project,' provides no usage conditions relative to siblings, and leaves behavioral safety aspects unaddressed.

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 0%, so the description must compensate. It explains the preset options, the behavioral effect of taper, and the overridable physics fields, adding genuine meaning beyond the schema. It does not, however, describe the 'bones' array or the 'project' parameter, leaving two of five parameters undocumented.

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 names a specific resource ('Spine 4.2 physics constraints') and a key behavior ('runtime secondary motion, no baked keys'), so the domain is clear. However, it lacks an explicit verb such as 'apply' or 'create,' making the exact action slightly ambiguous. It also does not distinguish this tool from the sibling 'secondary' or other rigging tools.

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?

There is no guidance on when to use this tool versus alternatives like 'secondary' or 'squash_stretch.' It lists preset values and override fields, but these are configuration details rather than usage conditions. An agent receives no when-to-use or when-not-to-use criteria.

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