add_lineart

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

With no annotations, the description carries the burden and does disclose useful behavior: units for thickness, the direction of the crease_angle tradeoff ('lower draws more lines'), and that intersection lines are optional. However, it never says whether this creates an object/modifier in the scene, how to undo or remove it, or any permission/dependency requirements — notable gaps for a mutation tool with zero annotation coverage.

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 a one-line purpose and a style hint before the Args block, and each arg line carries real information. The 'Returns' block is mildly redundant given an output schema exists, but it costs little.

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 7-parameter, zero-annotation, zero-schema-coverage tool, the description covers the purpose, every parameter's semantics and ranges, and the source/source_name relationship, and an output schema handles returns. It stops short of describing side effects on the scene or cleanup, which an agent would still need to infer.

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 0%, and the description compensates by documenting all seven parameters with meaning and valid ranges (thickness 0.0001–1.0 metres, crease_angle 0–3.1416 radians with the 2.443/140° anchor, RGBA component range, source enum semantics, and source_name's dependency on source). Only defaults and the color array's expected length are left implicit.

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?

Names a specific verb and resource (Add Line Art) and immediately explains what the result is: inked outlines generated from 3D geometry as seen by the active camera, plus the visual style it produces. An agent knows exactly what capability this tool provides without opening the schema.

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 only implied through the effect description ('gives renders a comic, technical or toon look'), which suggests a stylistic rendering workflow but never states when to reach for this versus e.g. shader-based or freestyle alternatives. No prerequisites or exclusions are given (e.g. whether a camera must exist).

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