get_body_kun_library

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

With no annotations, the description carries the full burden and does so well: 'only reads the catalog and never opens Blender or writes scenes' is an explicit side-effect guarantee, plus asset caveats (61 bones, matte ID colors, GLB loses native IK, not a verified 1:1 scan) that matter for reuse decisions. The gap is that 'the supplied helper' is referenced but never named or described.

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 scope land in the first sentence, followed by strictly supporting facts (rig requirement, fallback limitation, usage rule, side-effect guarantee). No sentence merely restates the name, and the disclaimer is placed where it matters rather than padding the opening.

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 zero-param read with no output schema and no annotations, the description covers purpose, constraints, side effects, and asset caveats. It is slightly thin on what is actually returned (entry names, paths, or color values) and does not name the helper it tells the agent to use.

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?

The tool takes zero parameters, so the baseline of 4 applies; there is nothing for the description to disambiguate at the argument level.

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 first sentence states a specific verb and resource: 'Locate the five saved Body-kun DX reference mannequins for reuse,' so an agent immediately knows this is a catalog-lookup, not a scene operation. It does not differentiate itself from rig-related siblings such as get_rig_constraints or get_skeleton_blueprint, which a reader might plausibly confuse it with.

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?

Usage is directive and concrete: 'Append with the supplied helper; never rebuild the mannequin per scene' rules out an obvious wrong approach. The Blender 5.1+ vs GLB-fallback split is a real selection criterion, though neither the helper nor a comparison with rig-blueprint siblings is named.

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