design_apply_grain

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

No annotations are provided, so the description carries the full behavioral burden. It implies a layer is added over the canvas, but does not state whether this is destructive, non-destructive, canvas-wide, reversible, or what permissions or side effects apply.

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?

The definition is a single front-loaded sentence with no filler or repetition. Every part of the sentence identifies the action and effect.

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 mutation-style filter tool with no annotations and no output schema, the description is too thin about behavioral consequences and layer interaction. The rich parameter schema compensates only for parameter-level detail.

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 schema already documents all four parameters with defaults and ranges. The description adds no parameter meaning beyond that, so the baseline of 3 is appropriate.

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 uses a specific verb ('Add') and resource ('film grain filter layer over the canvas'), making the primary effect clear. It names the filter type, but does not explicitly contrast it with sibling filter/texture tools such as design_apply_halftone or design_add_noise_texture.

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 sentence implies the tool is used to apply a film grain effect, but it gives no explicit when-to-use guidance, exclusions, or alternatives. An agent can infer the basic use case but must decide on its own when to choose this over related filter tools.

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