shade

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

Annotations declare destructiveHint=true and readOnlyHint=false, and the description adds real value beyond them: it discloses that the tool is 'cheap and exports as is', that weighted_normals installs a Weighted Normal modifier, that export_glb honors the normals while apply_modifiers is true, and that a later shade call removes it. It also bounds the destructiveness ('changes normals only'). Persistence of the modifier is the notable non-obvious behavior it surfaces.

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-loads the core action and mode semantics before the more advanced weighted-normals nuance, and every sentence carries information. It is dense and one continuous block rather than scannable, but nothing is filler.

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?

With four params, no output schema, and annotations present, the description covers mode behavior, the modifier side-effect, export interaction, and scope limits. An agent has enough to invoke it correctly; only the 'names' argument and error/edge behavior are unaddressed, which are minor.

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 description must carry the parameters, and it does for three of four: it explains each enum value of mode, what 'angle' controls (edges sharper than `angle` degrees stay sharp), and what weighted_normals=true does. Only 'names' is left implicit, but it is self-evident as the target meshes.

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 and resource ('Set shading of meshes') and then decomposes the three modes with concrete outcomes ('a cube stays crisp, a sphere becomes smooth'). It also explicitly distinguishes itself from sibling 'sculpt' by scope ('changes normals only'), so an agent can place it correctly among the many mesh-editing siblings.

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?

Gives clear conditions for the weighted_normals option ('Use it for parts with both bevels and flat chamfers, where no single angle works') and routes vertex-moving work to the alternative ('to move vertices use sculpt with op smooth'). No explicit when-not to shade at all, but the context for each mode/flag is well covered.

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