figma_set_node_fill

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

The description adds significant behavioral context beyond annotations: it reveals the tool walks to the first vector-type descendant for instances and supports both fill and stroke. Annotations only indicate idempotence and non-destructiveness, so this extra detail is valuable.

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: the first states purpose and key behavior, the second gives usage context. No redundant words; front-loaded with essential information.

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 setter tool with no output schema, the description covers core functionality and usage context. It could be more complete by explaining fallback behavior or return values, but it is adequate for an agent to understand when and how to invoke the tool.

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 schema already covers 75% of parameters with descriptions (variablePath, hexFallback, target). The description adds value by explaining the overall purpose of setting DS variables and the instance-walking behavior, though it does not detail all parameters individually.

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 tool sets a fill or stroke color variable on any node, and it highlights the special behavior for component instances (walking to first vector-type descendant). This distinguishes it from other color-related tools like figma_read_variable_values or figma_discover_library_variables.

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 advises using this tool 'to apply DS color variables to nodes after insertion,' providing clear context. However, it does not explicitly mention when to avoid using it or point to alternative tools for similar purposes, which would improve guidance.

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