design_add_fence

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

No annotations exist, so the description carries the full burden. It usefully signals that the call creates a new layer and defaults to foreground rendering, but says nothing about whether the layer stacks on top, how it interacts with existing depth lanes or atmosphere, or what the call returns or how to undo it.

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 short sentences, front-loaded with purpose before the rendering detail and preset list. The preset enumeration mildly duplicates the schema enum, but it functions as a quick-scan reference rather than 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?

For a 12-parameter tool with no annotations and no output schema, the description is on the thin side: it never explains the return value or how the optional seed/sag/atmosphere parameters affect the result. The rich schema compensates for parameter-level detail, but the behavioral layer is left mostly bare.

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 100%, so baseline is 3. The description repeats the four preset enum values (white-picket, stone-wall, ranch-rail, wire-fence) and loosely maps them to the alternate 'fenceStyle' enum, but adds no detail on sag, spacing, height, depthLane, or atmosphericMode beyond what the schema already documents.

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 ('Add a fence or wall silhouette layer') and enumerates the visual variants it produces. An agent can immediately tell this creates a foreground fence/wall layer, though the description never contrasts it with the many sibling 'design_add_*' foreground elements (treeline, building, rock, bridge).

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?

The phrase 'as foreground elements' implies usage context, but there is no explicit when-to-use, no prerequisites, and no routing to alternatives such as design_add_treeline or design_add_building for similar scene-dressing tasks. Guidance is implied rather than stated.

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