Describe a figure

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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds genuine value by disclosing the depth and shape of the returned data — that joints carry handles, parents, lengths, angles, thickness, shape and colour, plus fills, rig and keyframe placement — which matters because there is no output schema.

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?

Two sentences, front-loaded with the return payload and followed by the targeting rule. The long parenthetical list of joint attributes is dense but each element is informative; minor cost in readability rather than waste.

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?

With no output schema, the description carries the burden of explaining return values and does so thoroughly (joint attributes, fills, rig, keyframe). Parameter defaults and the project scoping are handled by the schema, so nothing critical is missing, though edge cases (e.g. what happens if neither uid nor figureTypeId is supplied) go unmentioned.

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 100%, so all four parameters (uid, frame, project, figureTypeId) are already documented in the schema, including frame defaulting to the playhead. The description's sentence about uid vs figureTypeId largely restates the schema's own descriptions, so it adds little beyond the baseline.

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 and resource ("Report one figure in full") and enumerates exactly what is returned: joint geometry (handle id, parent, length, angle, thickness, shape, colour), fills, rig, and keyframe position. This is clearly distinguishable from figure_list, which returns a collection rather than a full single-figure dump.

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?

Explicitly routes the caller between the two targeting modes: "Name an instance with uid, or a definition with figureTypeId." That is a real use-case decision the agent would otherwise have to infer. No explicit when-not guidance relative to figure_list or pose_evaluate, which keeps it below a 5.

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