set_fill_color

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

No annotations are provided, so the description bears full responsibility. It only notes that the node can be TextNode or FrameNode, but does not disclose whether the fill replaces or appends, what happens for unsupported node types, or any side effects. This is a significant gap.

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 sentence, making it concise, but it is poorly structured with a grammatical fragment ('can be TextNode or FrameNode'). Every sentence should earn its place; here it could be clearer.

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?

Given no output schema and no annotations, the description should provide more context about the operation (e.g., behavior on unsupported nodes, replacement vs. addition). It only mentions node type restrictions, leaving the rest to the user's guess.

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 each parameter (nodeId, r, g, b, a) is already documented. The tool description adds no additional parameter semantics. Baseline score of 3 is appropriate.

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 verb 'Set the fill color' and the resource 'a node in Figma', and specifies allowed node types (TextNode or FrameNode). This distinguishes it from siblings like set_stroke_color. However, the phrasing is awkward with missing punctuation, reducing clarity slightly.

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 such as set_stroke_color or set_effects. There is no mention of usage context, prerequisites, or 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.