set_fill

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

With no annotations provided, the description must carry the burden of behavioral disclosure. It implies a mutating action but does not state whether the operation replaces existing fills, merges them, or how it applies when multiple fill objects are supplied. Existing fill behavior and side effects are left completely unspecified.

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 with no filler. It immediately states the action, then summarizes supported fill kinds. Every word contributes to the purpose.

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?

The tool has 6 parameters, nested objects, no output schema, and close sibling tools, so the description must do more. It fails to explain how parameters interact (e.g., when to pass fills vs color vs gradient), whether multiple fills replace the existing fill list, or what the result/return value is. This is insufficient for correct invocation in ambiguous cases.

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 baseline is 3. The description adds a small amount of context by naming solid, linear, radial, and multiple fills, which maps loosely to the type enum and fills parameter. However, it also omits ANGULAR and DIAMOND which the schema lists, and it does not clarify relationships between color, gradient, fills, and opacity.

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 and resource ('Set fill on a node') and enumerates supported fill families (solid, linear gradient, radial gradient, multiple fills). It does not explicitly distinguish itself from the sibling set_gradient_fill or set_image_fill, but the core purpose is unambiguous.

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 usage guidance is provided. The description does not say when to use this tool versus set_gradient_fill or set_image_fill, nor does it mention prerequisites, exclusions, or preferred scenarios. The agent must infer selection purely from the tool name and schema.

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