design_add_field

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

With no annotations, the description carries the full burden. It usefully discloses render behavior — marks shrink toward the horizon, wind and seasonal tinting affect output — but says nothing about the mutation itself: whether a new layer is inserted, where in the stack it lands, whether it is reversible, or what state is required.

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?

Four short sentences, front-loaded with the purpose before the preset enumeration. The preset list largely duplicates the enum, but it is scannable and no sentence is pure 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 creation tool with no annotations and no output schema, the description covers intent and visuals well but leaves the mutation contract (layer insertion, ordering vs. depthLane, reversibility) and the effect of most parameters undocumented, which is a meaningful gap.

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 all 12 parameters are already documented including defaults and ranges. The description restates the preset list (already an enum) and gestures at wind/tint/color, adding little syntax or interaction meaning beyond the schema — baseline 3 applies.

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 vegetation field layer with depth-receding marks,' plus the rendering behavior (marks diminish toward the horizon). This clearly separates it from generic siblings like design_add_mark_field or design_add_snowfield, though it never names those alternatives explicitly.

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 — 'Add a vegetation field layer' tells the agent what it produces, and the preset list hints at scenarios, but there is no statement of when to choose this over design_add_mark_field, design_add_plant, or design_add_terrain_profile, and no prerequisites (e.g. an open sketch or active depth lane).

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