reach

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

With no annotations, the description carries the full burden. It usefully discloses that the hand orientation is preserved and that the return value is the residual wrist-to-target distance, and it explains pole side effects. It omits what happens when the target is unreachable or whether the existing arm pose is overwritten.

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 tight sentences: the primary behavior and return value come first, the pole side-effect second. No filler, and the most important fact (it moves the wrist to a point) is front-loaded.

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?

No output schema exists, and the description correctly covers the return value ('how far the wrist ended from the point'). Combined with reasonably rich schema descriptions for pole/frame/target, an agent has what it needs, though failure modes (unreachable target) are absent.

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 75% (side and target/frame are documented), and the description adds genuinely new meaning for 'pole' by explaining its effect on the elbow rather than just its format. It complements the schema rather than repeating it.

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 action (arm IK placing the wrist on a point) and a specific constraint (hand keeps its turn), which is enough to separate it from pose/move siblings like move_part or solve. It is clear but relies on domain jargon (poles, forearm clearance) that isn't fully unpacked.

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 one concrete usage scenario ('trying poles while the wrist stays put moves only the elbow... a way to clear a forearm'), which implies when the tool is useful. It never names an alternative sibling or states when not to use it, so selection guidance remains inferred.

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