select_rectangle

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

With no annotations, the description must carry the full burden of behavioral disclosure. The word 'Replace' indicates a destructive mutation of the current selection, but it does not explain coordinate origin, bounds checking, or whether the operation applies to the active image or layer. Minimal context is provided beyond the schema's parameters.

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 description is a single concise sentence with no wasted words. It is front-loaded and easy to parse. However, it is so brief that it borders on under-specification, lacking important explanatory content, though this is not a structural issue.

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?

Despite having an output schema, the description is incomplete for a five-parameter tool. It fails to specify coordinate system, units, whether the rectangle is anti-aliased, or how selection replacement interacts with existing selections. Sibling tools like select_ellipse likely share the need for such context, but this description does not provide it.

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%, and the description adds no meaning to any of the five parameters. It does not explain that x/y are top-left coordinates, width/height are in pixels, or how image_id identifies the target image. The agent must rely solely on parameter names, which are vague.

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, 'Replace', and identifies the resource as 'the selection', making the action clear. It distinguishes itself from sibling selection tools (e.g., select_ellipse, select_layer_alpha) by specifying 'rectangle'.

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?

No guidance is provided on when to use this tool versus alternatives. The description is purely functional and does not mention prerequisites, use cases, or exclusions, leaving the agent to infer usage from the schema and sibling names.

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