set_anim_retarget_source

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

Goes well beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=true). It discloses that the write runs inside an undo transaction and is saved, that an unloadable ref_pose_seq_path aborts before any mutation, that pre-existing values yield a no-op with changed=false/applied_count 0/saved=false and a note, and that a failed save sets success=false with save_error. This is exactly the mutation/failure context annotations cannot express.

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?

Purpose is front-loaded in the first sentence, followed by outcome edge cases and a returns line. Every sentence earns its place, though the explicit 'Returns: {...}' enumeration is somewhat dense and could be trimmed of low-value fields without losing meaning.

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, enumerating the return keys is necessary and done well, and the transaction/save/error behavior is fully covered. The one gap is the absence of any indication of when this tool is the right choice versus sibling retargeting tools, but for a narrowly-scoped mutation the description is otherwise complete.

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 the schema already documents all three parameters including the 'None'/empty clearing semantics for retarget_source and ref_pose_seq_path. The description's only added semantic is that an unloadable ref_pose_seq_path is an error, which is useful but marginal; baseline 3 is appropriate when the schema carries the load.

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 precise verb and resource: 'Set a UAnimSequence's retarget source (and optionally its retarget reference-pose sequence)'. An agent immediately knows the target asset type and the property being mutated. It does not name a sibling to contrast with (e.g. set_retarget_pose_bone_rotation, set_anim_additive_settings), so it falls short of full sibling differentiation.

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?

No guidance on when to choose this tool over the many related retarget/anim-sequence tools in the sibling list. The edge-case prose describes runtime outcomes (load failure, no-op, save failure) but never addresses when or when-not to invoke it, so there is effectively no usage routing.

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