set_fill_color

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

No annotations are present, so the description carries the burden of disclosing behavior. It mentions node type constraints but does not state whether existing fills are replaced, how multiple fills are handled, what happens for unsupported node types, or what the return behavior is.

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 and front-loaded with the action. However, the grammar is slightly awkward ('can be TextNode or FrameNode' lacks a relative pronoun), making it less fluid but still 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?

For a mutation tool with no annotations and no output schema, the description lacks critical context about return values, fill replacement behavior, and error conditions. It is minimal and not adequate for fully informed agent use.

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 all parameters (r, g, b, a, nodeId) are already documented. The description adds no parameter-specific meaning beyond what the schema provides, so baseline 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 action (set) and resource (fill color), with explicit node type constraints (TextNode or FrameNode). It distinguishes from sibling set_stroke_color by specifying 'fill' rather than 'stroke'.

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?

Usage is implied when the user wants to change fill color, but no explicit guidance is given about when to choose this vs set_stroke_color or other mutation tools. No exclusions or prerequisites are mentioned.

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