design_add_mark_field

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

With no annotations, the description carries the full burden of behavioral disclosure, and it only covers the aesthetic result. It never says this mutates document state by appending a layer, whether the operation is undoable, whether it requires an active sketch, or where in the stack the new layer lands relative to existing content.

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?

Two short sentences, front-loaded with the verb+resource and followed by the visual consequence; nothing is padded or repeated. It is tight, though the second sentence is elaboration rather than disambiguation, so it earns slightly less than a full mark.

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 10-parameter, zero-annotation, no-output-schema mutation tool, the description explains the visual output but omits activation requirements, layer interaction, and any hint about the exposed field shorthand. It is adequate to understand what the tool produces but thin for calling it correctly.

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 100% and the field parameter's shorthand grammar is fully documented in the schema, so the description does not need to restate it. The description adds no parameter meaning beyond the schema — not even a pointer to the notable field shorthand or density range — which is the expected baseline when the schema already does the work.

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+resource ("Add a mark-field layer") and backs it with the concrete visual outcome — short directional marks following a vector field, producing hatching/cross-hatching. An agent can picture the result, but the description never distinguishes it from close siblings like design_add_flow_lines or design_add_bristle_stroke, which also produce directional strokes.

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?

There is no guidance on when to reach for this versus flow lines, bristle strokes, or design_paint_layer, and no prerequisites are stated (e.g. whether a sketch must be open, whether a region must be selected first). The reader is left to infer usage entirely from the visual description.

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