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

No annotations are provided, so the description carries the full burden. It does disclose the return payload (CSS output, Web Animations API sample, sampling points), which is useful, but says nothing about control-point valid ranges, validation errors, or what happens when both name and points are supplied.

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 dense sentence that front-loads the toolbox category, the action, and the two input modes. It is efficient, though the packed parenthetical of preset names is slightly heavy.

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?

With no output schema the description helpfully summarizes the returned artifacts, but with 5 undocumented parameters, no annotations, and no stated defaults or mode exclusivity, an agent still lacks enough to call it confidently in edge 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 coverage is 0% and none of the 5 parameters are documented, so the description must compensate. It explains that a preset name (with examples and a count of 32) or four control points can be used, which maps loosely onto the name/x1/y1/x2/y2 fields, but it never states the ordering, ranges, or that the two modes are alternatives.

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 (generate) and resource (CSS cubic-bezier easing curves), plus the two input modes (a named preset among 32, or four control points) and the payload returned. It is clearly distinguishable from siblings like generate_keyframes and spring_to_css_linear.

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 by the two input modes, but the description never states when to pick this over the related motion siblings (spring_to_css_linear, generate_keyframes) or whether name and control points are mutually exclusive. Context exists but no exclusions or alternatives are named.

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