visual_hull

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

Annotations declare a non-destructive write (readOnlyHint=false, destructiveHint=false), and the description adds genuine behavioral context beyond them: outline detail fidelity and the limitation that the interior is a straight extrusion requiring later refinement. However, it omits key operational facts: whether existing geometry is replaced, whether front/side must be pre-authored outlines, and any failure modes or prerequisites.

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?

Three tightly-packed sentences that front-load the core mechanism, then the fidelity benefit, then the caveat and use case. Every sentence carries information; nothing is padded.

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 mutation tool with no output schema and zero schema-description coverage, the description covers what it does, when to use it, and its main limitation, which is solid. But it leaves the eight parameters and the input format (image paths? view names? authored outlines?) undocumented, which an agent needs before calling it.

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 only slightly, implicitly tying the front/side outlines to the intersection mechanism. It says nothing about the format of 'front' and 'side', what height_m controls, what simplify/threshold do, or what side_faces selects, leaving 8 parameters largely unexplained.

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 description gives a precise verb and mechanism: it makes a solid by extruding and intersecting the front and side outlines, so the agent knows exactly what geometry operation this is. It implicitly separates itself from siblings by naming sculpt and subdivide as follow-up tools, though it never distinguishes itself from close siblings like solidify, extrude_profile, or trace_outline. Clear, but not fully self-differentiating.

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?

It states a positive use case ('a precise first form of characters, props and vehicles') and a clear constraint ('refine curved surfaces afterwards with sculpt, subdivide'), routing the agent to the right follow-up tools. What's missing is an explicit when-not: it doesn't say when to prefer trace_outline, extrude_profile, or solid modeling instead.

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