spine_add_bone

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

No annotations are provided, so the description carries the full burden. It does disclose the insertion-order invariant and that it returns the resulting bone tree, which is genuinely useful. However, it omits whether the change is persisted, what happens on name collision, or how invalid parents are handled — significant for an unannotated mutation.

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?

The purpose and the ordering behavior are front-loaded, and the Args block is terse with no filler. Slight waste in the deprecation note, but overall efficient.

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 a 15-parameter mutation tool with zero annotations and zero schema descriptions, the description is far too thin — most parameters have no semantics anywhere. The presence of an output schema mitigates the need to explain return values, but the input side remains largely opaque.

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% across 15 parameters, so the description must compensate. It only explains four (inherit, transform, skin, color), leaving the geometric parameters (x, y, rotation, scale_x/y, shear_x/y, length), parent, project, and name undocumented, and it does not list the allowed `inherit` values exhaustively enough to be an enum reference.

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?

The opening sentence gives a specific verb and resource ('Add a setup-pose bone') and adds a distinguishing structural detail about insertion order. It's clear what the tool does, though it never explicitly contrasts with the sibling spine_update_bone.

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?

There is no statement of when to use this versus spine_update_bone or spine_add_attachment, and no prerequisites (e.g., the project must exist, parent must exist). Usage is only inferable from the phrase 'setup-pose bone'.

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