Paint: Stamp an image

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false, so the mutation/repeatability profile is covered structurally. The description adds that layers, filters, and undo behave uniformly across drawing tools, hinting the operation is reversible, but says nothing about how existing pixels at the target location are treated (replace vs. composite) — useful for a non-idempotent draw op.

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 tight paragraphs with the core action front-loaded and the source-type constraint immediately after. The final sentence about layers/filters/undo is slightly tangential but earns its place by clarifying cross-tool consistency.

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 13-parameter mutation tool with no output schema, the description covers the operation, source semantics, key transform options, and cross-tool layer/undo behavior. It leaves return/preview behavior to the schema, which documents it, so only minor gaps remain.

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?

With 13 parameters and only 62% schema description coverage, the description compensates by naming the meaning of source (canvas name or paint-root path, png/jpg/bmp), scale, rotate, opacity, blend, region crop, and tile. The unaddressed remainder (x, y, layer, preview, preview_size) is largely covered by schema descriptions.

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 ('Places another canvas or an image file onto this layer') and enumerates the supported source formats and transform options. An agent can distinguish it from paint_rect, paint_brush, or paint_transform without opening the schema.

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?

It gives setup context ('Target the canvas by name (created with paint_canvas) and optionally a layer index') but never states when to choose stamping over a sibling like paint_import or paint_transform, nor any when-not condition. Usage is implied rather than prescribed.

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