retime_character_motion

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

Annotations already flag this as a destructive, non-read-only, closed-world write. The description adds substantial context beyond that: single checked transaction, automatic snapshot/rollback, preservation of solved Point poses, verification of all joint key states, and an explicit exclusion of arbitrary tangent vectors and AI interpolation.

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?

Compact and front-loaded with the decisive scope ('2-8 complete synchronized character keys... ONE checked transaction'). But it is telegraphic to the point of ambiguity — 'Read back after timeout' and 'Preserves solved Point poses' assume internal vocabulary an agent may not share, so density partly costs clarity.

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 destructive multi-key mutation with no output schema and no parameter descriptions, the description does cover transactionality, rollback, verification, and scope restrictions. It still leaves the meaning of stabilize_contacts and the failure/timeout behavior underspecified for an operation this consequential.

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 carry the load, but it only gestures at the 'keys' payload (interpolation/easing weights, count limits) and leaves source, target, left_weight, right_weight, stabilize_contacts, and the id parameters entirely unexplained. The added meaning is real but far from compensating for a 0% coverage 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?

States a specific verb ('Retime') and resource ('character keys') with the scope quantified (2-8 keys) and the transaction semantics called out. It distinguishes itself from plain keyframe tools like set_keyframe by restricting to synchronized/exclusive IK character tracks, though it never names a sibling directly.

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 implied through constraints ('only exclusive IK character tracks', '2-8 complete synchronized character keys'), which tells the agent when the tool is valid and when it will not apply. However, no alternative tool is named for non-synchronized or non-IK cases, and there is no explicit when-to-prefer-this guidance.

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