design_apply_vignette

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

With no annotations at all, the description carries the full burden, and it only discloses that a layer is added. It does not say whether the effect is non-destructive, whether it applies to the whole canvas or the selected region, whether it appends to the layer stack or replaces something, or whether it can be undone. For an unannotated mutation tool this is a substantial gap.

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?

A single front-loaded sentence with zero waste; the resource comes first and the effect follows immediately.

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?

No annotations, no output schema, and a mutation that adds a layer — yet nothing about return value, target scope, or side effects. The description is too thin for a tool that mutates document structure.

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% with sensible ranges and defaults for color, radius, softness, and intensity, so the schema already does the semantic work. The description adds nothing about how these interact (e.g., that radius and intensity trade off), so the 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?

The description names a specific verb and resource ('Add a vignette filter layer') and states the visual effect ('darkens the edges of the canvas'), which clearly distinguishes it from the other design_apply_* filters such as design_apply_blur or design_apply_duotone. It falls short of 5 only because it never names a sibling or a discovery path like design_list_filters.

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 use this versus the nine other sibling filter tools, no prerequisites (does it need an active selection, artboard, or existing layer?), and no note on whether it stacks with other filters. The agent must infer all of that from the tool name alone.

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