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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds genuinely non-obvious behavior: pricing at ¥0.2/call, charged only on successful calls, with automatic refunds on failure or empty results — useful for an agent deciding whether to spend a call. It does not cover rate limits or empty-result semantics beyond the refund note.

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, front-loaded with what is returned before the use cases and the pricing caveat. No filler and nothing duplicated from the schema or annotations.

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 simple read-only lookup with no output schema, the description covers purpose, return fields, use cases and billing, which is enough to call it correctly. The remaining gap is input format for user_id and whether private/restricted accounts return partial data.

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%, so the two parameters are already documented and the baseline is 3. The description adds nothing about user_id format — whether it is a numeric UID, a RED profile ID, or a handle — which is the one ambiguity an agent could realistically hit.

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 and resource (获取小红书用户信息) and enumerates the returned fields (昵称、粉丝数、获赞数、简介、认证状态), which is more than a restatement of the name. It separates itself from note/post-oriented siblings by framing this as an account-entity lookup, though it never names a sibling explicitly.

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?

Gives concrete when-to-use scenarios: 达人筛选、账号画像、粉丝量级分组. That is clear contextual guidance, but there are no exclusions or pointers to alternatives (e.g. xhs_user_notes for the user's note list, or other platforms' user_info tools).

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