Place fixtures in 3D

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

With no annotations supplied, the description carries the full burden and does so: it states NO UNDO (Oops does not revert positions) and that the restore list holds every previous value, that writes are refused during patch copy, that rotations are renormalized so a single axis cannot be changed alone, that scale is silently ignored, and that read-back occurs a frame later with stated tolerances (0.1 mm, quaternion). That is exactly the destructive/reversibility and verification context an agent needs.

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?

Front-loads the core action and coordinate system before descending into layout kinds and return shapes, so an agent can stop reading early if it only needs a simple placement. It is dense and long, with some overlap against schema property descriptions (unit, follow, preview), but essentially every clause carries operational information.

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?

There is no output schema, so the description takes responsibility for the return contract: items with {fid, position, rotation, mirror_mesh?} on a clean success, the restore list, and the fuller per-write-step shape under detail: true. Combined with the refusal and no-undo notes, an agent has enough to call this correctly on the first attempt.

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?

Adds substantial meaning beyond the 67%-covered schema: it defines the arc angle convention (0° = stage left of centre, 90° = upstage, 180° = stage right), what 'follow' adds to rotation z, how mirror negates x and rotation y/z, that line spacing is inclusive from..to, and that position axes not given stay unchanged. It also restates the semantics of unit, preview, detail, verify and mirror_mesh in operational terms rather than mere labels.

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?

Opens with a specific verb and resource ('Set fixtures' position, rotation and mesh mirroring in the 3D stage') and pins down the coordinate convention (X stage left, Y upstage, Z up), which tells an agent exactly what domain of state this mutates. It also names gma3_fixture_positions as the read counterpart, but never contrasts itself with the sibling gma3_set_position, which is the most likely confusion point for a write-to-stage-position 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?

Gives concrete when-to-use conditions: preview: true to expand a plan without sending, and the explicit exclusion that the call is refused while the patch copy is open. It also directs the agent to read rotation via gma3_fixture_positions first. The missing piece is guidance on when to use this versus the programmer-oriented gma3_set_position.

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