Add Shape

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

Annotations provide basic safety info (readOnlyHint=false, destructiveHint=false). The description adds behavioral details: the shape layer becomes the active layer, shapes are non-destructive and scalable. This provides useful context beyond structured fields, though it omits potential side effects like clearing selection.

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 sentences with no filler: first sentence states action and resource, second adds behavior. Front-loaded and efficient.

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?

With 6 parameters (nested bounds), no output schema, and moderate complexity, the description covers key aspects: what it does, result (active layer), and property (non-destructive). It does not mention prerequisites like active document or error handling, but is adequate for an agent.

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?

The input schema has 100% description coverage, so the schema already explains all 6 parameters. The description does not add new meaning to parameters beyond stating the shape types. Baseline 3 is appropriate given high schema coverage.

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 clearly states the action ('Add a vector shape layer'), specifies the shape types ('rectangle or ellipse'), and distinguishes from sibling tools like photopea_add_fill_layer or photopea_add_text by focusing on vector shapes.

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 description implies when to use this tool (for vector shapes) and hints at advantages (non-destructive, resizable without quality loss), but does not explicitly contrast with other add tools or state when not to use it.

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