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

With no annotations, the description carries the full behavioral burden, yet it says nothing about the returned representation (presumably a CSS string), layer ordering, or how the per-layer 'opacity' and 'color' inputs are combined into the emitted shadow. For a generator whose output is the whole point, this is a meaningful 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?

A single sentence with no filler and the essential concept front-loaded. It is efficiently sized, though the brevity contributes to the missing detail noted in other dimensions.

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 tool taking a nested object array with seven sub-properties, no annotations, and no output schema, the description omits layer field meanings, default behavior, and output format. An agent cannot confidently construct a valid multi-layer call from this text alone.

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 0% and the single parameter is a nested array of objects with seven undocumented sub-fields (offsetX, offsetY, blur, spread, color, inset, opacity). The phrase 'one or more layers' acknowledges the array but conveys nothing about what a layer contains, leaving the 0% coverage uncompensated.

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 ('build') and resource ('CSS box-shadow value') with the input shape ('one or more layers'). It is clearly distinguishable from siblings like css_gradient_build and css_border_radius_build by the resource name, though it largely restates the tool name rather than adding new framing.

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 statement of when to use this versus alternatives, no prerequisites, and no mention of related tools such as css_format or css_contrast_check. The agent must infer usage entirely from the name.

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