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 one real behavioral trait — the output includes a 減少動態 (prefers-reduced-motion) mode — which is useful. However it says nothing about the return shape, whether duration/delay are in ms or s, or how iterations behaves, so the disclosure is thin for a generator with no annotation coverage.

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 compact segments with the core action front-loaded before the preset list. The bracket prefix is slightly redundant but costs little, and the long preset enumeration earns its place by filling a schema gap.

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 five-parameter generator with no annotations and no output schema, the description omits too much: units and ranges for delay/duration, easing format, iterations semantics (e.g. 'infinite'), and what the returned keyframe string looks like. Only the preset values are fully covered.

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 there are no enums in the schema, so the description must compensate for all five params. It enumerates the 15 valid preset values (genuinely valuable since the schema types preset as a bare string), but delay, duration, easing, and iterations are left completely unexplained — no units, format, or defaults.

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 (產生) and resource (CSS @keyframes 動畫), and notes it includes a reduced-motion variant. This clearly separates it from siblings like motion__generate_easing or motion__generate_gradient, though it never names those alternatives directly.

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 when-to-use or when-not guidance is given beyond the toolbox tag. An agent cannot tell from the text when to pick this versus motion__generate_easing, motion__spring_to_css_linear, or motion__compare_animation_libraries. The preset enumeration is data, not routing guidance.

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