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

Annotations declare readOnlyHint and openWorldHint=false, so the safety profile is covered. The description adds behavior beyond annotations: it returns modern CSS, a fallback with precomputed stops, and the stop colors, plus notes the OKLab gray-middle avoidance. It doesn't mention rate limits or error conditions, but for a pure computation tool that's less critical.

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, front-loaded with the core action and output, then a useful color-space note. Efficient with little waste, though the OKLab note could be folded in more tightly.

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 5-parameter, read-only computation tool with no output schema, the description covers purpose, output shape, and a key behavioral trait (fallback generation). Missing only explicit when-to-use guidance versus siblings.

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 coverage is 60%, with enums documented and some parameter descriptions present. The description doesn't add parameter syntax or format details beyond the schema's own color examples and stop counts. Baseline 3 applies because the schema does most of the heavy lifting.

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?

Clear verb+resource: builds a CSS gradient with named interpolation spaces. Sibling tools are all color-utility functions, but the description doesn't explicitly differentiate from e.g. convert_color or mix_colors, though the gradient output makes it fairly distinct.

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 implies when to use OkLab vs sRGB for gradients, but does not state when to use this tool versus alternatives like convert_color or mix_colors. No explicit exclusions or alternatives are given.

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