apply_pixelate

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

With no annotations supplied, the description must carry the full behavioral burden; it does disclose that the operation targets a layer and returns a status dict, and that layer/image default to the active layer and index 0. However, it never states whether the pixelation is applied destructively in place, whether it affects the whole layer or only the selection, or whether it is undoable — key facts for an image mutation.

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 purpose sentence is front-loaded and the parameter list is easy to scan, with no filler prose. The default values in the list duplicate the schema defaults, which is minor but slightly redundant.

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 three-parameter, no-required-args mutation tool with no annotations and no output schema, the definition covers parameters and return type adequately but omits side-effect, scope (selection vs full layer), and undoability information. An agent could call it correctly but not predict its impact.

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 0%, so the description must compensate, and it does: all three parameters are explained with units ('block_size in pixels'), default values, and the layer_name fallback to the active layer. That is meaningful added meaning beyond the bare schema, though the interaction between layer_name and image_index is not spelled out.

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 opens with a specific verb and resource ('Pixelate a layer') plus the effect mechanism ('mosaic/block effect'), which is unambiguous. It does not distinguish itself from neighboring filter tools such as apply_noise, apply_emboss, or blur, so differentiation among siblings is left to the reader.

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 choose this tool over alternatives like blur, apply_noise, or gegl_apply_filter, and no preconditions are stated. The only usage hint is implicit in the parameter defaults (active layer, image 0).

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