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

The annotations already declare this is a read-only, closed-world operation, and the description adds real value beyond that: the exact payload shape (thumb 320 / full 960 absolute URLs with kind/credit/license) and the semantics of the three kind values. It does not say what happens when the id is unknown or whether the id is case-sensitive.

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?

Front-loaded with the verb and the lookup key, then a compact enumeration of the return payload, then a short glossary of kind values. It is dense but every clause carries information; the only mild cost is the single long colon-chained sentence.

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 carries the burden of describing the return value and does so concretely, including image size variants and the kind taxonomy. Only error/not-found behavior and id-matching rules are left unspecified.

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% and the schema already documents that id accepts either a style id (synthwave) or a Chinese name (合成器波). The description restates this without adding new format or resolution rules, so the baseline of 3 applies.

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 (get one style) and resource, and enumerates exactly what is returned: definition, generation prompt, feeling words, era/region, and image assets. The sibling tools are all word_* lookups in a different domain, so this tool is unambiguously distinguishable.

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 usage (look up a single style by id or Chinese name) but never states when to use it versus when not to, and names no alternative tool. Since no sibling style-list/search tool is present, the routing risk is low, but there is still no explicit guidance.

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