control_rig_add_control

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

No annotations are provided, so the description carries the full burden. It discloses that the tool edits the asset via the 'save' parameter, but does not explain side effects, potential failures (e.g., duplicate control names), whether the rig must be loaded, or what happens to existing controls. For a mutation tool with zero annotation coverage, this is a significant gap.

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 well-structured with a clear one-sentence purpose, a bulleted args list, a KB reference, and an example. Each line serves a purpose, though it is longer than necessary. The front-loaded purpose makes it easy to scan.

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?

Given the tool's complexity (13 params, no annotations, no schema descriptions), the parameter coverage is strong and an output schema exists. However, it lacks context on prerequisites (e.g., existing rig asset, parent element requirements), error handling, and how this fits into a broader rig-creation workflow. The KB reference helps but is not a substitute for inline guidance.

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, and it does thoroughly. Every parameter is explained with its purpose and valid values (e.g., 'parent_type: BONE, NULL, or CONTROL', 'control_type: EULER_TRANSFORM, POSITION...'), and optional defaults are clarified. This adds substantial meaning beyond the bare schema.

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 states 'Add an animation control to a Control Rig hierarchy' with a specific verb, resource, and context. It clearly distinguishes this from sibling tools like control_rig_create or control_rig_add_constraint by naming the exact operation.

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 purpose statement implies when to use the tool, but there is no explicit guidance on when not to use it or comparisons to alternatives. The example shows a minimal call, which hints at usage, but there is no mention of prerequisites like the rig asset needing to exist or parent element validation.

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