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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely new behavioral facts beyond that: a per-call price of ¥0.1, billing only on successful calls, and automatic refund on failure or empty results — exactly the kind of cost/failure context an agent cannot get from structured fields.

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?

Four short sentences with zero filler: purpose, return payload, use cases, and pricing/failure behavior are each front-loaded and each earn their place. Nothing repeats the tool name or the schema.

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 compensates by listing the returned fields, and the pricing/refund behavior rounds out what an agent needs. The only real gap is that a first-time caller is not told where a sec_user_id comes from (e.g., that it is obtainable from keyword search results).

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%, with sec_user_id documented as '作者sec_uid' and _token as a fallback auth token, so the schema carries the parameter burden. The description adds no extra meaning about where to obtain a sec_user_id or how it differs from a numeric uid; baseline 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?

The description states a specific verb and resource ('获取抖音作者详细信息') and enumerates the exact return fields (nickname, follower count, likes, bio, verification status), so the agent knows precisely what it gets. It does not explicitly name a sibling to avoid, but within the Douyin tool family there is no competing author-profile tool, so the distinction is effectively unambiguous.

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?

It names concrete use cases ('达人筛选、账号画像或粉丝量级分组') that give clear context for when to reach for this tool. What is missing is any exclusion or alternative (e.g., when to use douyin_keyword_search first to obtain a sec_user_id, or when video-level tools are the better choice).

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