Update the fill, stroke, corner radius, or opacity of an existing shape layer to change its appearance. Modify styling without recreating the shape.
Modifies the fill, stroke, corner radius, or opacity of an existing shape layer.
| Name | Required | Description | Default |
|---|---|---|---|
| layerId | Yes | Layer ID | |
| opacity | No | Opacity (0 to 1) | |
| fillColor | No | Hex fill color | |
| strokeColor | No | Hex stroke color | |
| strokeWidth | No | Stroke width | |
| cornerRadius | No | Corner radius |
Changes observed during successful MCP inspections.
v1.0.7Does 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 does not disclose whether the update is partial or full, whether unspecified properties are reset, what permissions or preconditions are required, whether the change is reversible, or what happens if the layer is not a shape layer.
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, front-loaded sentence that states the action and affected properties with no wasted words or unnecessary preamble.
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 6-parameter mutation tool with no annotations and no output schema, the description is incomplete. It omits partial-update semantics, error behavior, permission requirements, and return behavior, leaving the agent with little beyond the schema to invoke the tool correctly.
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%, so the schema already documents all six parameters. The description lists the modifiable style categories, but adds no syntax, defaults, or constraints beyond what the schema provides (for example, opacity range is only in the schema).
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 states a specific verb ('Modifies') and resource ('shape layer'), and enumerates the style properties affected (fill, stroke, corner radius, opacity), which distinguishes it from sibling tools like shape_add and text_update_style. However, it does not explicitly name any sibling alternative or clarify scope beyond 'existing layer'.
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 usage by saying 'existing shape layer,' suggesting the tool is for already-created layers, but it provides no explicit when-to-use guidance, no when-not-to-use guidance, and no alternatives for related tasks such as changing text style or adding a new shape.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.