Evaluate the rig

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

Annotations already declare readOnlyHint and idempotentHint, so safety is covered; the description adds the coordinate space (canvas pixels), that segments and IK controller state are included, and that segments are per-segment endpoints. With no output schema it still leaves the returned data structure unnamed, which keeps it below a 5.

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?

Three tight sentences: what is returned, when to use it, and how to specify the time; the operative information is front-loaded. The final sentence largely restates the tick schema field, so a small amount of redundancy remains.

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 evaluation tool with no output schema, the description adequately sketches the return payload (joints, segment endpoints, IK state) and the time-selection mechanism. It does not describe result shape or whether uids filtering changes the payload layout, a minor gap.

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 schema already documents tick, frame, uids, project and includeSegments. The description adds only the tick-vs-keyframe precision distinction (and that tick overrides frame-based selection), which is a marginal gain over the schema's own wording.

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?

Names a specific verb (read/evaluate) and a precise resource (the solved rig at a point in the animation), and enumerates what the read yields: joint positions in canvas pixels, segment start/end points, and IK controller state. This is clearly distinct from the mutation siblings pose_set, pose_reset and pose_ik_set without needing their schemas.

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?

Gives concrete usage contexts: locate a hand or foot before modifying it, and verify a pose after modifying it. It does not explicitly rule out alternatives (e.g. figure_describe or pose_ik_set) for overlapping questions, so there is no exclusion guidance.

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