spine_add_ik_constraint

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

With no annotations, the description carries the load well: it discloses the target-exclusion validation rule, the default constraint ordering ('after existing constraints'), the softness falloff behavior, and the scale-to-reach semantics of compress/stretch/uniform. It does not mention required preconditions (existing project/animation) or failure behavior, leaving a modest gap.

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-loaded with the core semantics, then an Args block keyed to parameter names — easy to scan and map to the schema. The example values ('thigh, shin', 'foot-target') earn their place; no filler sentences.

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 an 11-parameter mutation tool with no annotations, the description covers the domain semantics, constraints, defaults, and the per-parameter meaning, and an output schema exists so return values need not be explained. An agent has enough to build a correct call.

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 0%, so the 11 parameters rely entirely on the prose, and it documents bones, target (with constraint), mix (0..1), bend_positive, softness, order, and the three scale flags. Only `project` and `name` go undocumented, which is a small residual gap given how obvious they are in context.

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+resource ('Add an IK constraint') and immediately explains the two operational modes (1-bone point-at vs 2-bone limb chain). This distinguishes it from the sibling constraint tools (spine_add_transform_constraint, spine_add_path_constraint, spine_add_physics_constraint) implicitly by name, though it never names them explicitly.

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?

Explains which mode applies to which rig topology (one bone points at target; two bones as parent/child bend like a limb) and notes the target must not be among bones or their children. It also flags that animation is driven by the timeline 'ik' channel. Missing is explicit guidance on when to choose IK over transform/path/physics constraints.

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