anim_set_controller

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

The description explicitly says switching controllers clears existing keys on the track, which adds specific destructive behavior beyond the generic destructiveHint=true annotation. The mutation implied by 'assign/switch' is consistent with readOnlyHint=false, so there is no contradiction.

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 short and front-loaded: purpose, selection guidance, and destructive warning in that order. The bilingual repetition is redundant for an agent but not excessive, so the structure is only mildly penalized.

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 mutating 3-parameter tool, the description plus fully covered schema cover the main inputs and the key side effect. However, it leaves the controller value mismatch between enum and suggested examples unresolved and does not clarify effects when multiple objects are targeted, so an agent could still call it incorrectly.

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 baseline is 3. The description adds property-type-to-controller mappings, but the suggested values (bezier_position, euler_xyz, tcb_rotation, bezier_float) do not align cleanly with the enum values (Bezier, Euler, TCB, List), and bezier_float appears nowhere in the enum or examples; this added guidance may lead to invalid calls.

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 opens with a clear verb and resource: assigning a controller to a property, and lists the supported controller types. It is distinguishable from nearby animation tools like anim_set_key or anim_set_interpolation by emphasizing controller assignment and the key-clearing side effect, though it does not explicitly name a sibling tool.

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?

It gives concrete controller recommendations per property kind (bezier_position for position, euler_xyz/tcb_rotation for rotation, bezier_float for scalars), which helps choose parameters. However, it does not state when to prefer this tool over alternatives such as anim_set_interpolation or anim_set_key, or when not to use it; the choice is only implied.

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