Add a rectangle or ellipse to a specific slide with an optional hex fill color to build slide layouts.
Add a rectangle or ellipse shape to a specific slide with optional fill color.
| Name | Required | Description | Default |
|---|---|---|---|
| x | Yes | X position | |
| y | Yes | Y position | |
| width | Yes | Width in pixels | |
| height | Yes | Height in pixels | |
| slideId | Yes | The node ID of the slide | |
| fillColor | No | Hex color e.g. '#FF5733' | #CCCCCC |
| shapeType | Yes | Shape type |
Changes observed during successful MCP inspections.
v1.46.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full disclosure burden and largely drops it. It does not say what is returned (presumably a new shape node), what happens with an invalid slideId, whether the shape is layered on top of existing content, or how x/y are anchored (top-left origin?), even though the label 'position' is ambiguous.
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?
A single well-formed sentence with the verb and resource front-loaded and the optional parameter acknowledged at the end. It is efficient, though it leaves out information an agent arguably needs.
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?
There is no output schema and no annotations, so the description should at minimum say what a successful call yields (e.g., the created shape's node ID) and confirm the coordinate origin for placement. With 7 parameters and 6 required, the schema covers inputs well, but the return behavior and positional semantics remain undocumented.
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%, with units (pixels), ranges, an enum for shapeType and a hex pattern/default for fillColor already documented in the schema. The description only restates that fill color is optional and that shapes are rectangle/ellipse, adding no syntax or anchoring semantics beyond the schema — baseline 3.
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 (add) and resource (shape on a specific slide) and enumerates the allowed shape kinds (rectangle, ellipse). The 'to a specific slide' phrasing implicitly separates it from figjam_create_shape_with_text and figma_add_text_to_slide, but no sibling is named or contrasted.
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 only implies when to use it via the verb 'Add'; there is no explicit when-to-use statement, no prerequisites (e.g., a valid slide must exist), and no routing away from alternatives like figma_add_text_to_slide or figjam_create_shape_with_text.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.